Good idea. The most important thing YC provides is an effective social network. You're connected to piers going through the same process, so you have people that understand what you're going through. In addition, YC provides advise/access to people who have been where you're attempting to go and facilitates interactions with investors that would be difficult to arrange on your own. You probably couldn't offer the same networking opportunities, but if someone is having a hard time finding a cofounder, being Cambridge at MIT would probably help.
I agree with all your points. That's why my offer doesn't really compete with YC. In fact, you have to have applied to YC and been turned down in order to be considered for this option.
I can't provide the peer-group support and advice that PG does. But, I can hopefully start you down the process (I'm involved with half a dozen local startups, not including my own, and have decent contacts on both the entrepreneurial side and the investment side of the community).
