Well, if Apple is as fast as usual in implementing software solutions for hardware capabilities, by 2011 you might be able to use your Nvidia GPUs together and move from one to the other on the fly.
I know, I know, the fact that PC users have that already is because PC companies don't care about their customers and implement it in a crappy way, while Apple takes its time to do it properly (anyone still believes this crap?). And yet, they can use it and we, Apple users, still have to reboot to switch GPUs.
Does anyone still remember the Blu-Ray software support that Apple was supposed to include first in Leopard and then in each revision? Can you explain to video professionals why they have to buy a PC on top of the Mac if they want to author BR discs? How many thousands of a second is gonna take for the fanboys to answer: "physical media are gonna disappear so Apple is right in not giving you options"?.
With regards to the RAM memory, I think it was Bill Gates who said in the 80s: "I don't see why anyone would need more than 640K of memory". I guess 32 Gb will be standard in less than 5 years.