Also check out the Beta of you get the chance and make up your own mind how it compares to Destiny.

I'm really interested in The Division, I remember seeing all the E3 stuff, and some of the more new marketing material, and it looks like Destinys biggest contender. Once the game comes out, I can see a lot of Destiny players being persuaded by their friends to buy it (like what happened with Destiny). I don't believe the game will be a "Destiny Killer", but it's going to take a decent chunk of its core audience, some will inevitably return once more content is available for Destiny. Personally, I think trying to play both the Division and Destiny simultaneously will be very difficult. Imagine playing Destiny on 2 different consoles, it's soul destroying! But a handful do manage it well.