Pretty much what it says on the tin. That doesn't really qualify as "summer" for a release, I know, but so it goes.
The linux stuff derailed me more than I thought it would, and in general we're just trying not to rush around so much as we used to. I think the expansion will be better for it. There are also a number of us traveling at various points (Erik is at PAX East, we have some stuff in October, etc), which makes our availability for release dates kind of dodgy, too. Rather than risking things coming out the other end in an unpolished fashion, simply using the November date made more sense.
BUT! As the title indicates, you won't have to wait that long to get your mitts on it.
For those who have been around through the earlier AI War expansions (all of them prior to VOTM), you'll recall that what we did was open up preorders for the expansion through our site as soon as we had the first ship or two implemented, heh. And then you had access to that all through development. With this expansion we're not going in THAT early, but you can get it a good month to month and a half prior to release via a preorder.
Basically we'll be doing our preorders-that-come-with-a-beta when the expansion is almost completely feature-complete, but still isn't fully balanced or polished yet. Because, as with any undertaking this large, we'll definitely want your feedback on that! There may be a few achievements missing at that point, or some other little minor stuff, but all the big features I want to have fully in place when you first see it so that you aren't guessing about my intents for the features. If something is "off" you know it isn't because it isn't just incomplete or something, and can let us know.