According to Maury Brown, despite the groundswell of support, or rather complaints, regarding the MLB blackout policies last season, it looks like nothing is going to change.
Here's the blackout map for MLB Extra Innings:
The internet isn't advanced enough yet to blow up that gif to a large enough size to correctly determine just what teams you can watch in Iowa. One of the really striking things about living in eastern Iowa (the more populated side of the state) is that just about every major Midwestern city is exactly the same distance away: 300 miles. With local cable coverage random, Iowans are caught on the periphery of Chicago, St. Louis, Minnesota, Kansas City and Milwaukee, it's probably just easier for Iowans to adopt, say, the Orioles as their team.
Other horrible places to try to watch baseball include: southern Nevada, Oklahoma, Arkansas and parts of the Mid-South. Transplated Red Sox and Yankees fans are fine just about anywhere however, so no worries.
The best? How about North Carolina? Nominally Nats territory (laughing) it looks like they can still watch the Braves, while all the transplants from the Megalopolis can still obnoxiously watch their hometown teams.