I live in VT and Montreal is about 2 hours from here, so Montreal moving out of town means no more baseball games up there....
Also, the Vermont Expos (single-A rookie league team) would probably move out of Burlington if the team went south.
On the other hand, I dislike Olympic Stadium. So much less character than Fenway Park...
BUT, since Montreal HAS to move, Washington DC isn't a bad place. It may hurt the Baltimore Orioles being so close, which is why they are working agaisnt it.
It would be really interesting to have baseball in Puerto Rico, but I just don't see that working out.