Year's, the T would be an absolute shitshow. I'm not really sure how they would deal with that.
The actual infrastructure for events would be pretty easy, though. The Garden and Agganis are in good shape, and I don't see why Gillette (as well as the Dunkin Donuts Center in Providence) wouldn't be an option if they beef up the commuter rail lines to the south (I would kill for this for entirely selfish reasons). It's currently only a 30-40 minute train ride there, so it's not hard to imagine an express line putting that ride under 30 minutes.
Edit: Whoops, I forgot that they already have an express line to Foxboro for events. There were talks of the MBTA buying the tracks to Foxboro in 2010 that apparently stalled. It's currently a freight track that the MBTA uses on game days.
I dunno. I don't really want them here, because as others have said, living in the area would really suck for a month. But I'm not a MA taxpayer right now, and they would be pretty cool to attend, so what the hell?
Maybe baseball will be reinstated as an Olympic sport by then so we can get a new Sox stadium out of it?