Very cool - the return of an East Coast presence for YC is a good thing for New York and Boston based early entrepreneurs.
Of course, not that there's anything wrong with that. It's just that I doubt this is a good thing for the overall east coast entrepreneur community.
I've always emphasized that seed funding isn't a local business in the way VC is. Startups come to YC from all over and can go anywhere they want afterward. I honestly believe the optimal route for founders who want to live in NYC would be to come to the Bay Area for YC, then move back to NYC afterward-- just as a lot of New Yorkers choose to go to Boston for college, then move back to NYC afterward.