Only homerun calls will be officiated by the instant replay now, although this is going to open the door to more of these types of calls in the future. I can see foul ball calls being reversed in a year or two from now, but this would also have to be approved by the teams, owners, and the umpires themselves.
In the San Francisco Chronicle, one of my favorite quotes came from Cubs manager, Lou Pinella, "When an NFL coach drops the red handkerchief, I go to the refrigerator for 4-5 minutes."
Maybe some more snack food companies will jump on board for MLB ads this way, I don't know. The Phillies had a controversial call tonight against the Mets when the ball hit the runner in the base path, oddly enough it was a 'foul ball' called by the umpire. Instant replay doesn't matter on that type of call. Managers of MLB clubs feel different towards the replay, some like it, and some do not. Bud Selig, Commish of the MLB, didn't want instant replay either but do to the vote by the GM's representing the baseball teams, had to act upon what they wanted.
Quote from the AP:
Replay ball! Umpires will be allowed to check video on home run calls starting Thursday after Major League Baseball, guardian of America's most traditional sport, reversed its decades-long opposition to instant replay.
"Like everything else in life, there are times that you have to make an adjustment," baseball commissioner Bud Selig said following Tuesday's announcement. "My opposition to unlimited instant replay is still very much in play. I really think that the game has prospered for well over a century now doing things the way we did it."
The 74-year-old Selig, who described himself as "old fashioned" and an admirer of baseball's "human element," softened his opposition following a rash of blown calls this year.
For now, video will be used only on so-called "boundary calls," such as determining whether fly balls went over the fence, whether potential home runs were fair or foul and whether there was fan interference on potential home runs.
"Any time you try to change something in baseball, it's both emotional and difficult," Selig said. "There's been some concern that, well, if you start here, look what it's going to lead to. Not as long as I'm the commissioner."