Not sure if this has been covered yet, but:

MLB wants to expand replay to include fair-or-foul calls, "whether a fly ball or line drive was trapped" and fan interference all around the ballpark. Umpires still must give their approval and it's uncertain whether the extra replay will be in place by opening day.

Personally, I'm not a fan of replay on fair-or-foul calls, but there it is. My guess is that we're going to see a lot more close calls get called "fair" and then (maybe) rescinded on replay, for the same reasons that NFL refs consistently err on the side of ruling a fumble on the field--if you reverse a "foul" call, it's hard to tell what might have happened, but it's generally really straightforward to reverse a "fair" call. I think it's a matter of taste, but for a call that umps get correct so often, I'd rather see focus on improvement directed elsewhere. We'll see how it plays out, I know to a large degree I'm swimming upstream on this issue.

Eliminating a practice of some teams, there is a prohibition on "taxi squads" -- calling up players from the minors and not activating them.

Do teams really do this? I can't think of any recent examples. Usually the Twins are in dire need of the player they call up since they tend to have a wait-and-see approach to players going on the DL.

And there's at least one issue still to be decided.

For the postseason, the sides agreed to negotiate on tiebreaker rules -- do teams tied for the last wild-card berth meet on the field, or will the tie be broken by a formula?

I hope it's on the field. I hate tiebreakers with the unbalanced schedule. I mean, I guess I hate the wild card with the unbalanced schedule, but tiebreakers are a further injustice (in my book.) I suppose the issue is that this means the players have to play more games without additional compensation, since paying players extra for the playoff game would conceivably provide an incentive on some level for teams to want to tie to end the season. Yeah, it's a little far-fetched, but given its history with gambling and game fixing, I think they are right to be cautious.

I'm probably getting ahead of myself, though--travel and schedule are likely bigger culprits. Who wants to be the team that plays three games in three days in three different cities? Well, I guess I'd rather do that than sit at home because I lost a tiebreaker, but I suppose on some level that's a matter of taste, too.

Quick uniform number switches will be a thing of the past.

Players must tell the commissioner's office by July 31 of the preceding year if they want a new jersey. That is, unless "the player (or someone on his behalf) purchases the existing finished goods inventory of apparel containing the player's jersey number." As in, every replica jersey, jacket, T-shirt, mug and anything else with a number that's anywhere in stock.

I wonder what made this a pressing issue. It seems like most players that switch their number spontaneously are either accommodating a teammate or pretty unknown. This also makes me wonder if, say, the NBA got burned when Kobe switched his number and MLB didn't want that to happen to them. (Unsure on how the timing works there.) I'd guess the major ramification here is if a team makes a big free agent acquisition and the new guy wants an occupied number, the new guy is going to have to buy a whole bunch of jerseys to make it happen.

The deal also bans players and team officials from asking official scorers to reconsider decisions -- clubs must instead send video to MLB to appeal calls -- and increases punishments for slow-moving hitters and pitchers, raising pace-of-game fines up to $10,000 each for the sixth violation and beyond.

Anything that reduces bias on the part of official scorekeepers is a plus in my book. The scorekeepers don't get paid enough to deal with players complaining about their decisions anyway. Not a big fan of the pace-of-game fines. Does the league get fined every time the players are ready to play and the commercial break isn't over yet?

That's about it, except for no corporate tats. Have there been any high-profile cases of this? I can imagine some corporation might pay good money for a forearm tattoo.