As far as anime go, Cowboy Bebop's not a bad one to adapt. The art style's fairly realistic (no huge eyes or extremely exaggerated body proportions...unless you count Faye), it stays away from a lot of the gags like giant sweat drops, and the story-telling style is more laid back and subtle than with other anime. The series has always had more of a live-action feel to it, at least that's how I've always felt; it's not a fantasy series, and while it is sci fi (western), it's on the believable side. None of the technological developments feel too far out there for the distance they're set into the future.
With as advanced as CG is now, they'd have no problem pulling off--convincingly--any of the aerial stunts the ships perform. The rest of the action in the series is on a pretty realistic human scale. So it's just a matter of good casting. I'd still like to see Spike as a tall, lanky guy, and Jet had better keep his bald head (I find it one of his more endearing qualities, and there just aren't enough bald guys in movies who are cool as Jet). The one who I can see being hardest to cast is Ed, though. You'd have to find a young teenage girl who's talented enough to pull off that level of randomness.
Assuming this doesn't fall by the wayside...I'd definitely love to see it.
(Western-made adaptation of an anime that I loved: Speed Racer. I haven't had that much fun at the movies in ages.)