There's a lot of people wondering if the 13" MBPs would have been a lot better with a Core i3 processor, but everything has been just hangups over perceived old vs. new technology, and really the only thing the Core i3 adds is Hyper-Threading, but it doesn't have Turbo Boost, which helps the Core i5/i7s tremendously. Let's compare using Geekbench since it is cross-platform and one of the few available sources of info...
Core 2 Duo P8600 2.4GHz (~3362)
http://browse.geekbench.ca/geekbench2/search?q=MacBookPro7,1+P8600&commit=Search
vs.
Core i3 330m 2.13GHz (~3472)
http://browse.geekbench.ca/geekbench2/search?q=Core+i3+330&commit=Search
Core 2 Duo P8800 2.66GHz (~3700)
http://browse.geekbench.ca/geekbench2/search?q=MacBookPro7,1+P8800&commit=Search
vs.
Core i3 350m 2.26GHz (~3680)
http://browse.geekbench.ca/geekbench2/search?q=Core+i3+350+2.27&commit=Search
As you can see in both cases, the difference is pretty minimal indeed, and in single threaded applications, the C2D will easily outdo the Core i3 which lacks Turbo Boost and runs at lower clock rates.
And you get a 320M instead of Intel HD graphics with the new 13".
The Geekbench results from the old 15/17" to the new 15/17" are quite an order of magnitude better.
So unless people are expecting Core i5 processors in the 13", sticking to the C2D was actually a good decision, and given the differences between 2.4 and 2.53 isn't so large, one is far better buying the base 13" and then putting the money saved towards a good 7.2k HDD or SSD.
Note - I took averages of the 32-bit numbers and added them.
Note 2 - The C2D Pxxxx are 25W TDP processors, which are more efficient than the Core i3 which are 35W TDP processors. Less heat, better battery life from C2Ds.
Core 2 Duo P8600 2.4GHz (~3362)
http://browse.geekbench.ca/geekbench2/search?q=MacBookPro7,1+P8600&commit=Search
vs.
Core i3 330m 2.13GHz (~3472)
http://browse.geekbench.ca/geekbench2/search?q=Core+i3+330&commit=Search
Core 2 Duo P8800 2.66GHz (~3700)
http://browse.geekbench.ca/geekbench2/search?q=MacBookPro7,1+P8800&commit=Search
vs.
Core i3 350m 2.26GHz (~3680)
http://browse.geekbench.ca/geekbench2/search?q=Core+i3+350+2.27&commit=Search
As you can see in both cases, the difference is pretty minimal indeed, and in single threaded applications, the C2D will easily outdo the Core i3 which lacks Turbo Boost and runs at lower clock rates.
And you get a 320M instead of Intel HD graphics with the new 13".
The Geekbench results from the old 15/17" to the new 15/17" are quite an order of magnitude better.
So unless people are expecting Core i5 processors in the 13", sticking to the C2D was actually a good decision, and given the differences between 2.4 and 2.53 isn't so large, one is far better buying the base 13" and then putting the money saved towards a good 7.2k HDD or SSD.
Note - I took averages of the 32-bit numbers and added them.
Note 2 - The C2D Pxxxx are 25W TDP processors, which are more efficient than the Core i3 which are 35W TDP processors. Less heat, better battery life from C2Ds.