I doubt that will be the order, since they like to rotate AL-NL. Philly had it in 1996?/SD in the early 1990s?, so it makes sense for Cincy to get it first and they'll probably be after the Marlins. As Selig has said, when the topic has come up the demand is a lot greater now than it was two decades ago. He has stated how he used to have to offer incentives to host.
Great American has never hosted before, so not much of a surprise.
For what it's worth, here is a list of current MLB stadiums that haven't hosted yet:
Great American (CIN)
Citizens Bank (PHI)
New Yankee (NYY)
Mets get the 2013 bid, as do the Twins in 2014 and Reds in 2015.
EDIT: Tropicana isn't getting it. Sorry, but that place is a dump and the fans don't deserve it.
I'm really surprised that Philadelphia hasn't gotten one yet. I would predict they get 2016. Yankees will probably have to wait longer since they hosted the final year of Old Yankee Stadium. So for 2017-2019 I could see the league going to San Diego, DC, and Miami in some order.
Hopefully MLB returns the ASG festivities to Camden Yards for the park's 30th anniversary in 2022, if not earlier.
Mark Lerner when he's asked about the subject has played the "age" card as in his dad is 87 and it be nice to allow him to see it. The area around the stadium is pretty boring and although they are expecting more development (which has been expected for the past 5 years), I'm sure MLB wants to see it actually completed before they award it.
I doubt Yankee Stadium is hosting anytime soon since the Mets are hosting and they just hosted 5 years ago. If this were the NBA, where they don't mind doing that, I could see it. The NBA seems to be big at keeping the All-Star games in warm cities since it's the dead of winter.
They'll probably want to NOT have it at OPACY and Nats Park in back-to-back years. OPACY would also be the first relatively new ballpark to host twice, but it was also the first. As you can see though, a lot more NL stadiums in demand than AL stadiums so that works in the Orioles favor.