I have a 13" 2.26 C2D MBP and a 15" i5. Before I bought the 13", just to have another computer around the house, I always bought 15" models. I love the 15" speed, but after using the 13", it feels like I'm carrying a brick house around. I'll likely never buy another 15". I can't imagine the 17". Might as well just buy a 21" iMac. Seriously, go for the 13". Great machine -- perfect for the couch or in an airplane. Hopefully we'll be seeing an i3 flavor since it seems Apple has resolved the video card issue w/ Intel.
thats the issue the 17 size.