I'll probably get it, if for no other reason than to grab a few new ideas and to keep up-to-date on what has and hasn't been converted to 4e yet. I enjoy designing things for 4e (especially monsters) even though I haven't played it since the first three or four months after it came out. Our group has mostly switched over to Star Wars Saga Edition and World of Darkness, so when we do break for D&D I try to push for a 3.5 campaign, since most of our group prefers playing with that ruleset.
I'm rather torn about the artwork, though. Overall the quality is much better than early 3.5e and I feel like I'm actually looking through an illustrated bestiary, rather than just some book with a bunch of pencil and ink sketches by often mediocre artists (no offense intended to any 3.5e artists - there was some really good artwork out there, especially towards the end, but most of it just wasn't to my tastes). On the other hand, as a few others have already mentioned, too many of the monsters have been reduced to Generic Ugly Beasty #X. I would like to see a lot more variety in the future - hopefully as they begin statting up some of the more obscure and bizarre creatures we'll see a move in the right direction.
Another thing I'm not too keen about is the the rewritting of the planes, but that is neither here nor there and is easily fixed by adding in a few new creature origins.