i7!
I went to the store to check the difference between the 15" glossy and the antiglare. What I didn't know was that I'd fall in love with the 17"antiglare, that was the only size available there with that option. It's great, but back home I got a 13" I'm currently using and it made it very clear that the 17" would be just to being for couch surfing.
I decided for the custom 15" hi-res antiglare and 500GB 7200rpm.
Besides that... buying a C2D now that the new came out would be right only if it was an absolute great deal.
Cost - Benefit... Everything I buy, I have to think of it as an investment. How much will I be able to get for it later?