A few months ago, even a few weeks ago, it looked as if the final details of baseball's bold new replay world were going to be dropped into place at the January owners meetings.

Uh, not so fast.

One slight problem: MLB still hasn't cut a deal with either the players' or umpires' unions. Not on replay. Not on changes in the rules regarding collisions at home plate.

So while owners will be briefed at Thursday's meeting on both of these seismic changes in their sport, it still isn't clear whether they will vote formally -- or what they would actually vote on if they vote at all.

Two prominent members of the committee in charge of both issues -- Atlanta Braves president John Schuerholz and MLB's executive vice president for baseball operations, Joe Torre -- both assured ESPN.com Wednesday that they were "confident" the sport was moving toward agreements with the players and umpires.

But nobody ever promised them this would be easy. Or quick. Or perfect. And it's a good thing -- because every time they try to put one piece of the new replay system in place, it seems to throw another piece out of whack, kind of like Rubik's Cube.