There's a lot! Its really obvious they've taken everything they've learned from the first game and applied it to the second. They've said it in a few interviews and everything they're really focusing on end game content, making sure they have enough available. When you reach the end you can progress through "World Tiers" 1-5 which increases the available gear score drops. super cool! not to mention dark zone has its own leveling system.
They even have a 8 man raid coming out in a week or two! I'm not yet geared for it but should be in time!
Its well worth the purchase! I sent @Cainanth a gpu, so he's going to pick up the game come monday (sometime this week).