Several reasons:
1. Malifaux 2.0 was mentioned by a rules marshal.
http://www.wyrd-games.net/showthread.php?38402-Yin-Mass-of-Viscera-and-the-old-Attack-vs-attack-question&p=497460&viewfull=1#post497460
2. I've noticed that the boards have slowed down a little in the past monthish. Could be holiday related or it could be because the most prolific posters are posting in the hidden playtest forums instead of here.
3. With Gencon being about 7 months away I'm making a semi educated guess that for the new book to be available at gencon it(and the cards/models which will both go through a similar process) has to be ready for printing in about 2-3 months. Thus lending weight to my thoughts that the playtest is alive and well. The time line for the book is probably something like 2 weeks to review proofs, 2 weeks for printer to make changes as noted in the review, 2 more weeks for final proofs to be approved, about 5-8 weeks in the "print que", a few days or a week for printing/binding, 3-6 weeks for the container(s) to ship. That is a rough guess of 14-20 weeks from the end of the playtest to the books/cards being printed and shipped. If I were the one in charge I'd want a month or more of "cushion" to handle the inevitable snafu's that will appear. Especially after the last promise that 70% would be available to purchase at the con. I'm not complaining, just thinking that Wyrd will be more cautious about their promises from now on.
That brings us to the playtest being done at least 18-24 weeks BEFORE Gencon. Thats roughly 4-6 months. So IF I'm correct that the playtest for book five (Special Forces? 2.0?) is going on now then this is the best time to talk about it. Later today I'll ask a friend who is a book publisher is my timeline guesses are pretty close.
Regardless of when or if 2.0 happens after the last few errata's I'm sure Wyrd will take the time to do things right. Or at least as right as humanly possible.