It would be interesting to see a Mexico or Canada team added to the ranks. Oakland seems like the worst choice because they have been down that road too many times already. You have to expand two teams when you do one so if I had the magic ability to choose I would want Mexico City and Toronto.
There was chatter in the past about expanding with a London team but I think that would be a bad idea. Between the jet lag and rather extreme travel time, I don't think it would work even though it would be awesome.