So for anyone willing to star this idea up, you would be doing allot of people a favor. Expecially me.
Just offer walk through's, pros and cons on themes, tutorials on themes, list their limitations, how to optimize the code etc...Offer an affiliate link to all themes you Tutorialize (don't even know if that's a word), make money!
It's an awesome idea, one than I am not willing to do myself or pay others to do.
So here's a great idea for anyone dedicated to build it. Good luck