What they need to do away with, since there is a Wild Card slot, is the unbalanced schedule. How is that fair to teams in the AL East, like Baltimore persay? The Twins get to play the mediocre central squads 18 per, while the Orioles face the Sox, TB, Tor, and NY for that same number. Yet, each are vying for the WC. I understand that they want to put the emphasis on divisional play, and titles, but it's somewhat unfair IMO.
As for adding a second WC, how could you? That would mean 5 playoff teams. What would the playoff scenario be then? A bye for the first place finisher, while the 4 other teams play a best of 5 series? That doesn't work because no team would want to have 6-10 days off while the other series are played. Adding a 5th team would require some extremely out of the box tinkering, that a traditionalist sport like baseball, wouldn't be likely to accept. On top of that, is the money aspect that all these leagues not employ, where they care nothing about the fans, and only care about making sure every single game is televised individually, so no two games are on at the same time.
Some out of the box idea's would be to move back to 2 divisions, and add 4 WC teams. The 4 WC teams would play a best of 3 series, begining the day after the season is over, with the first series of the divisional round being played on day 4 after the series. This would suck for the WC teams, but hey, win the division then. It would mean only a 3 day layoff for the waiting division winner. The problem though, is what you do when there is a rainout. Hardly an ideal platform regardless.
Another option is to shorten the season by a week to ten days, using the old 154 game schedule from yesteryear, and have 8 teams make the playoffs like they do in the other sports. This would add one more series to the length of the current playoff system. Shortening the season would mean no games well into the cold weather. The problem with this is that it cheapens the regular season for the traditionalists, while owners and the league wouldn't want to lose 8 games X 30 teams. That's a lot of $$ to give up. Oh, and I'm sure the union wouldn't want that 5% (8 fewer games) deducted from their annual paychecks.
There are other possible options, but none of which that all parties involved, would agree to.