He's continued to do quite well sales-wise, actually, as far as I can see from the data available. The Omen Machine debuted at #1 on the New York Times Bestseller list, The Third Kingdom debuted at #5, and Severed Souls debuted at #4. (For comparison, the last three main Sword of Truth books debuted at #2, #1, and #2.) The more recent books do have somewhat less staying power on the list than the original sequence, but it's still a level of success most writers would kill for.
Gregory Maguire's Wicked: The Life and Times of the Wicked Witch of the West is free at several US e-tailers for the day. Here's an Amazon link: http://www.amazon.com/Wicked-Life-Times-Witch-Years-ebook/dp/B000FC14JY/
Part of the reason I'm not especially invested in Mixon's report (although I appreciate the visibility it and Martin's signal boost brought to Sriduangkaew's behavior) is that I think it was a mistake to use the tools of statistical analysis on a largely-deleted body of online writings. It's simply not possible to be precise about which bile was targeted at what, and you're limited to what particular people who speak up happen to have remembered and/or screencapped, and so you open yourself up to (frankly asinine) rules-lawyering about what percentage of her targets can be labeled "punching up," where you draw the line between harsh reviews and insults, etc. The value of Mixon's work is in the underlying data, which demonstrate the full range of Sriduangkaew's behavior, not in graphs and figures.
I do think that it's pretty tacky for people who present themselves as caring about the place of women and POC in SFF to spend a great deal of time arguing over just how disproportionately Sriduangkaew targeted those groups, as if there's some magic number of women and POC that would be acceptable as collateral damage in some imagined battle against straight white dudes. Rochita Loenen-Ruiz, Tricia Sullivan, Cindy Pon, Athena Andreadis, Rachel Manija Brown, and many others deserve better than that.
This report (whose author has zero online or fandom history prior to turning up in vigorous defense of Sriduangkaew, and is very possibly a sock identity for one of her other defenders) has pretty clearly been in the making for a while; the reason the links don't work is that they date from a time when archived versions of the Requires Hate blog were still available. Sriduangkaew has since changed the blog's robots.txt settings to hide those archived versions. Which says a lot about the credibility of claims that she didn't do anything offensive.
I have no investment in Mixon, her report, or her Hugo, so I'm not going to wade through 60,000 words of case-by-case quibbling that attempts to minimize and obfuscate obnoxious behavior that I witnessed for myself in real time. Certain of Sriduankaew's behaviors would be defensible as acerbic reviewing if they existed in an isolated context. But they don't. They exist in a context of violent and scatological rhetoric, interpersonal toxicity, and persistent harassment. This is someone who just the other day tweeted that an anon meme that's critical of her should "drown in your own fucking vomit, you worthless wastes of oxygen." I'm hardly one for discourse policing, but there's a limit somewhere.
His sales are much more than respectable in the long term, but they're not the kind of thing that's going to make Penguin clear the decks and rush to meet or approximate a date that was given to a few thousand fans on the Internet. Two years would be unusual, but since we're in August and the manuscript isn't quite finalized yet, we're actually talking maybe a year and a half, which is not shocking. It's on the long side, and it is quite possible that the last six months or so is purely because of whatever this vague-but-hyped announcement involves, but not really unusual. It takes someone who's going to make the bestseller list to get a real rush to publication, and Williams hasn't done that in over 20 years. A return to Osten Ard could very well change that... with the kind of full promotional cycle the book is now getting.
Edit: another factor, of course, is lead times. If Williams were likely to be delivering the series for one-per-calendar-year publication, there'd be more incentive to get book one out ASAP. But since he's more a one-every-two-or-three-years writer when it comes to epic fantasy, delaying book one a little will, as someone noted upthread, only reduce the gap between later volumes. By then, one hopes, there will be even more anxious, anticipatory readers than there are now.
He's still got some stuff under contract with them, and declared in a comment on one of Vox Day's blog posts that "All I said was that I will not be sending any new manuscript their way until I am recompensed for this insult. The manuscripts currently in the pipeline I expect to be edited and sold as per my contractual agreements with Tor." As someone said in another venue, he's probably about to discover just how thoroughly Tor can bury him while still honoring the letter of his contract.
A publisher as large as Penguin is going to have a very busy schedule, so it's not really surprising that the soonest they could give the book the promotion and distribution it deserves is Spring 2017. A year and a half from a largely complete manuscript to publication is pretty common in the industry, and despite being a huge seller overall Williams doesn't have the kind of immediate fanbase hunger that causes other epic fantasy writers to get rushed to publication.
Some Robin Hobb e-book deals, presumably to promote Fool's Quest. I imagine these will be US-only, but it can't hurt to check. I've linked to Amazon, but the deals seem mostly to be good at multiple sites:
The Rain Wilds Chronicles are discounted, to $0.99 for the first book and $1.99 for the other three. Amazon links: www.amazon.com/Dragon-Keeper-Rain-Wilds-Chronicles-ebook/dp/B00338QEUG 2 3 4
Also, the e-omnibus of the entire Soldier Son trilogy is $2.99: www.amazon.com/Soldier-Son-Trilogy-Bundle-Renegades-ebook/dp/B007Z4SH5O
And, while this isn't a new discount, Assassin's Apprentice is still $1.99: Amazon link.
Edit: OK, no idea why two of those links wouldn't format right, but I've left them in as plain text.
The question isn't whether it's plausible within the fiction for Fitz not to put things together within a certain timeframe; the question is whether it's satisfying in literary terms to make readers wait hundreds of pages across two books for characters to discover things the readers already knew. In small doses dramatic irony can be potent, but when overplayed and hammered home it can also frustrate, especially in a series that is, ah, not exactly fast-paced in other respects. I enjoyed Fool's Quest very much-- it reactivated my enthusiasm for the setting and the characters, which Fool's Assassin had failed to do-- but structurally, it has some real issues.
Advance review copies of the whole book, both physical and digital, have been out for a while. (I have a print version myself, though I haven't started reading yet.) And digital ARCs, like all e-books, are easily pirated, even ahead of the release date.
For me the issue isn't so much that Half the World and Half a War are necessarily weaker (though Half the World has some middle-book problems and the Thorn/Brand "they like each other and don't know it!" stuff is trite) as that they don't really bring anything new to the table in terms of themes, characterization, setting, or style. As more of the same goes, they're very well done, and I quite enjoyed Half a War, but Half a King does in 270 pages everything the others do in a total of 720. And the insult banter and portentous thematic declarations really start to pall after a while. But so it goes, with fantasy trilogies...
I think a publisher date is more likely than a retailer date to be one that was real at some point. But that doesn't mean they're always current. The rights guide linked above listed a September date, with a note that the manuscript was due in May. Since we're now two months past that due date and the manuscript is apparently not finished (unless it is and Lynch just hasn't mentioned that on social media), I'd say both September and October are unlikely, and we're fast approaching the point where the book will be bumped out of 2015 entirely.