Instant Replay in Baseball

I just heard about the new implementation of Instant Replay in baseball later this year.  It's about time with all the questionable calls umpires have made this year.  I know people will think this will just make games longer but I believe its only going to be used on home runs in question.  It doesn't really affect the Cubs much with the basket and all but I think it will be good for the game.  I mean in the past when the umpires weren't sure what to call they would have a little pow-wow anyway so at least they can review the play instead of wasting time saying to each other "I didn't see it.  Did you? Okay well then let's guess."  Anybody have any comments??