What people have been asking me, though, is whether they should get the i5 or the i7 MacBook Pro. Personally, I think the low-end i5 is more than sufficient for most tasks (its about 15% slower but costs 25% less). Granted, its got less drive space and less video card memory but its still zippy. If, however, you want the fastest MacBook Pro available then go ahead and get an i7; you are paying a premium for the performance but at least its not a steep premium!
Personally, if I were to buy a new MacBook Pro today, Id get one with an i5 processor and spend the money I saved on upgrading the RAM to 8GB.
Source : http://www.primatelabs.ca/blog/2010/04/macbookpro-benchmarks/