I know I'll be the only one here on this thread but I figure I'd start it anyway.
Let me start by educating the uneducated with a few definitions...
MotoGp : GP is the 'GranPrix' of motorcycle racing in the world. They are 1000cc prototype bikes that are made and designed for racing and speed, nothing else. They are bikes that are not mas produced for market sales. Only Ducati has a GP bike that was produced for public sale, the Desmosedici D16-RR (16 valve Race Replica). Ducati only made 200 of them and you could be the proud owner of one for a mere $70,000.
SBK : FIM World Superbike Championship is the premier class of Superbike racing in the world. A 'superbike' is basically no different then the 1000cc sport bikes you see on the street. They are only modified in the brakes and suspension and other parts to reduce weight. Very little of the engine and other parts are changed from what you get from your local dealer.
AMA : American Motorcycle Association is the class we have here in the U.S. The AMA has a few classes that can be confusing. They have a superbike class (1000cc) , as well as a sportbike class (600cc - 800cc). The sportbike class are basically bikes strait off the showroom floor of your local dealer with some safety changes for racing it.
These are the only street bike racing you'll see on TV(SPEED TV). There are others around the world (obviously) that we don't see here in the States.
I hope I can get others excited about this. If you ride a bike you can appreciate this sport and how these guys can race at speeds reaching 200mph and cornering at speeds of 130-150 with there knee dragging the ground. If enough show interest I'll try keeping everyone updated.