Batter switching from right to left handed

[mcrowder]

Can someone confirm or deny this for me:

With that both-handed pitcher in the minors 2 years ago, there was talk of making a rule that the pitcher had to make known which arm he was throwing with before the batter entered the box. There was other talk of enforcing it the other way around.

If there's no rule (and assume the pitcher in the stretch, where it's obvious which way he's pitching), what prevents a never-ending stalemate of batter switching, then pitcher switching, etc, or the batter standing outside the box waiting for the pitcher to touch the rubber, and stepping out if the pitcher steps off the rubber to change.

This is MLB. Doubt this would affect many lower levels ... but it's a good "what-if".