So, I am considering the new 12in PB but I know that Apple tends to offload a lot of their OS onto the GPU. I'm sure the 12in PB graphics chip is fine for now, but what do people think about its long term viability? Am I going to be obsolete in 2 years? Is the 15in with the ATI that much better? I'd rather get the 12in for its form factor, and I will not be doing any real hard core gaming on it. But, if people say the 15in is $500 better, I'd consider it. Thanks!