Some people (ie Slashdot) think that Apple may actually have leaked that info on purpose to build hype for the event. Wouldn't surprise me; rumour sites are a good source of publicity. In that case, they may have an even bigger surprise for the conference.
Can't wait... this might be my cue to switch. I am planning to buy a laptop for Uni next summer, maybe I might even buy a desktop before that, if I can afford it.