personally, i think brand k's zx6rr is gonna be the one to beat. if you go by recent performance, the r6. if you go historically, the cbr.
like most people, i haven't ridden of them.
but here's why i'm going with the zx6rr. it has adjustable swingarm pivot. i figure if brand-k is building that into their bike, they must be making a real effort at success.
the r6 will probably be about the same improvement over the old one as the r1 was last year. which is minor. it'll be a cool bike, but i don't think it'll be much better than last years. but in all fairness, does it need to be better at all.
the cbr is a honda. they build quality stuff. but every honda i ever rode, except for the 93-4 900rr, reminded me of a wrench. they get the job done, but don't have any soul. and the underseat exhaust says to me that they know they're getting their butts kicked everywhere else, we need a gimic.
the 636 seems like it'll be something less than the 6rr.
the gsxr is in the weird spot of being yesterday's bike.