LinkAll those features that were locked behind a "Gold" membership are now free. This is all retroactive, so previous games like Gears of War and Halo 2 now have it all unlocked. From the wiki, that means:
# Multiplayer matchmaking with friends
# TruSkill matchmaking
# Multiplayer achievements
# Cross-platform gameplay
In addition, they are adding a new marketplace similar to what the Xbox has. Trailers, demos, and other such stuff.
This might be a "too little too late" thing, but at least its a step in the right direction.