Scott Moritz from The Street took an old AppleInsider rumor and timepegged it to the Friday launch on October the 26th. The Street's rumor history is long and storied, but they're most recently noted for saying that iPhone users were to get 18-months of free AT&T service, so I rate this rumor at 0% probability of likelihood. Maybe this is the same source. [The Street]
The most logical upgrade is Mac Book will get the new motherboards like the Pros do (so from 2.16 to 2.2). A less likely thing to happen would be a price drop. So the entry level white Mac Book will be $999 and the high end white Mac book will be $1199 and who knows? Maybe the black Mac book will be $1199 as well and they'll stop this "200 dollars more for 40 extra GB and black matte" bullshit.