It'll be in the tri-state/East PA. Not many places can meet that 50,000 person quota of talent.
I've heard Philly thrown in the comments, and I think that city, and NY share the best odds. And I know for some it would suck for it to go there, but if we are talking the ability to fill those spots, the winner is there. Philly would draw from the bastion of NJ and Eastern PA along with the core city. If not Philly, NY.
Both would be perfect.
In terms of damn smart talent, one just has to look at where the IVY's are positioned. Along with dozens of other excellent schools. Transit wise, culture wise, the region is bar to none. Access to fortune 500's, connectivity, global power center, popularity in drawing new comers, well... its good at that.
That Northeast Corridor is looking more viable day by day. NY and Philly and D.C. will be within the top 5 choices.