They'll take out the "content" that "Hot Coffee" is using and rerelease the game.
They'll take a big hit on having to recall games from store shelves and create new CDs.
Since it's a third party application that is modifying the game code, rather than just entering some form of cheat code, I think the ESRB is wrong to change the rating despite the fact that the content is part of the game that's just been disabled.
Take-Two will likely be a bit more careful to strip developers toys out of their games in the future.
The game will still be sold with the content if was intended to ship with. They'll likely get a good advertising boost out of all this, and the version that's being made into Adults Only will be come a collector's item.
the code exists in the console version of the games, not just the PC version; it is not a mod, it's more like a cheat code to unlock the sex mini-game