The game I'm looking for is designed around all of its mechanics from the ground up and is balanced appropriately through systems that make sense for those elements. As far as I'm concerned, in the right context, there's kind of no such thing as a bad idea, only bad execution. Destiny has a shot for me precisely because it's doing its own thing and they know that these tertiary elements are going to impact the base mechanics already, something that would have been impossible to predict when Halo's core was built. This generation's Halo games tried to fit new ideas into the old context without upsetting that initial balance, and that core didn't always mesh with them very well which resulted in the myriad issues that cropped up. Starting from scratch with all of that in mind, there's the potential for that not to be an issue.
Whether the new stuff will be executed well is a much bigger question, and I have my doubts about some of what they're saying. I think caution is totally healthy when reading their plans for multiplayer, but mostly I'm just excited to see what solutions they arrive at. Even if I don't agree with what they do, they've got a whole new set of challenges facing them and success or not, they always do something interesting.