Currently instant replay is:
"Major League Baseball will institute the use of instant replay on Thursday to determine disputed home run calls -- fair or foul, in or out of the ballpark, fan interference -- Commissioner Bud Selig announced on Tuesday." http://mlb.mlb.com/news/article.jsp?ymd=20080826&content_id=3370519&vkey=news_mlb&fext=.jsp&c_id=mlb
If yes, what do you want it to expand to. And get ready for a terrible call at some point in the playoffs.
I think it should be expanded to...
- plays at the plate (expands to all bases in world series)
- fair or foul all around (if a foul is fair, give the runner a ground rule double, and if those on base are running use the +1 system) - with today's awkward stadiums it will be needed
- this isn't really a point for replay but use a system like the NHL (have an MLB official declare if a replay should be done) along with the umpires (some have shown they do not want to do replays because of ego issues)
Using replay for strike zone is out of the question for me, no way. Along with did he swing or not.