Well If you are buying a new laptop and you would like it to last a good 2-3 years then your better off getting a Core-I7. Yes, you don't need it at the moment but in the long run your laptop well retain more value and be able to run games at a later time with out the need to upgrade the CPU.
i7 is of course better than i5, but because the GPU (while better than I had thought) is still not that great, most games are going to run into trouble with the GPU. For that reason, getting an i7 probably isn't worth it, because almost no games are going to need that good of a processor with a GTS 335m.
I don't think it's worth it, i5 is already great and i7 would make your computer pretty out of balance.
I agree with the other users on the issue of the i7 vs. i5. The i7 is probably unnecessary for what you will be using your laptop for. If you want more information on processors and what affects their power and speed you can check out this helpful guide on PC Scout: http://www.microsoft.com/Windows/pc-scout/laptop-speed-....
GTS 335M is powerful enough to run games fine. You won't be able to max recent stuff, but medium settings should work for most games. The i7 is a CPU that could max recent games IF it had a GPU like a Mobility Radeon HD 5870. The GTS 335M is nowhere near that. You don't need the i7.
Actually thats quite wrong, the the i7 and i5 in question are of the UM version(i5-520UM, i7-640UM).
upgrading the CPU in such a system is pretty much unrealistic.
The i7's cache is 1mb larger and about 14% faster, the price is about 14% higher as well so you pretty much get the larger cache "for free".
I'd definitely go for the i7.