The NFL becomes the double national pastime sport of the USA, if past events are any indicator.

Maybe they'll create a new televised sport if baseball doesn't start on time next year, crypto currency baseball idk.

No major league players are allowed to perform team activities- no practice, no in-house rehab for injured players, no spring training or regular season games if the lockout lasts that long, and free agents aren't allowed to sign with a team or negotiate their contract (not sure how this effects arbitration-eligible players)

The MLB is no longer allowed to use the likeness of any current players' union member- already seeing the effects of this one. mlb dot com is pretty much a history site at this point, players' jerseys are no longer for sale, banners with players on them have been taken down at stadiums, etc. I'm not sure if/how this'll effect tv broadcasting (it probably will for MLB network and any local station owned by the team, unsure about channels like ESPN).

I'm sure there's a lot of stuff I'm missing, but this is the bulk of the immediate effects. None of this can change until a new CBA is in place and we have no idea when that'll actually happen. All we can do is hope the players get more out of the negotiations than the owners.

Also, none of this affects minor league players (but part of the MLBPA negotiations could cover the working conditions of minor leaguers, or at least keep them from being quite as fucked over if/when they make it to the majors)