Portland won't get a team - they're talking about moving the AAA team out of there, and moving them down to San Diego (the team is a AAA affiliate of the Padres). Vegas will never get a team, because it's Vegas (which is sad - I think a team would do good there).
Indianapolis is another big city without a team.
I think it's hard for them to discuss expansion again, when it was just a couple of years ago they were talking about contraction, and getting rid of the Twins and Expos.
This is "the year of the pitcher". Maybe we're finally seeing pitching catch up. Every expansion dilutes the pitching pool even more. Plus, with 5 starters the norm - it's even though to find quality pitchers to round out rotations.
I'd love to see some realignment, and to see another two expansion teams. I just doubt that it will happen. Plus, if you move into every open market now, that leaves no negotiation room for any team if they're trying to get a new stadium. (Where are they going to threaten to move to?).
They've shot down the 15 teams in each league idea - that would require Interleague play every day of the season (dilutes that product). And moving the Twins to the AL West won't happen, either - they're too far east. KC used to complain when they were in the AL West - the games would start too late. (It's tough when you're two time zones away from your primary opponents).