New details on the second season came out over the weekend.
Screenshot from a video game showing various soldiers in different military style gear. Each are holding weapons as they walk around an environment filled with large shipping containers.

Infinity Ward says that a Hardcore game mode is coming to Call of Duty: Modern Warfare 2 when Season 02 drops on February 15. They didn't say much about the Hardcore mode outside of there being no in-game HUD. Hardcore also typically enables friendly fire and lowers the time to kill (TTK), but those features have yet to be confirmed for this particular Hardcore mode.

When it comes to the DMZ, we know that there will be "new missions" along with a "new Exclusion Zone" and some difficulty tuning. On the Warzone 2.0 side of things, there have already been some changes made, with more to come in Season 02. Right now, players will be able to find more cash to loot throughout the map. Prices have also been balanced a bit to "give you more bang for your buck."

Season 02 for Modern Warfare 2 was recently pushed back from February 1 to February 15. This should give you a little cushion to wrap up those Season 01 Battle Passes if you have any remaining items left to unlock.

This week, Infinity Ward and all 5,700 Call of Duty studios are expected to release a new deep-dive blog to go into the nitty and the gritty details on Season 02 updates and changes.