AFAIK, last year's Suzuki Hayabusa holds the title of fastest production motorcycle. They "neutered" them this year...an agreement amongst the Japanese manufacturers to artificially limit the big bikes to 300kph. For "safety". Like you're more likely to survive a 186mph crash vs. a 200mph crash. Sheesh. This year's Kawasaki ZX-12R could have challenged the Busa for top speed honors were it not for this "agreement". Not that I'd ever test the top end on one of these beasts anyway, I've done around 145 on my bike and it's scary as hell.
Fausto