I started up MCC/Halo Combat Evolved on Normal and I quickly grew bored with how easy it was. I am not very good but there was little challenge from the average enemy. I dialed it up to Heroic and it's a lot more fun. There were a few areas which were difficult and required several attempts to progress, but so far most of those are manageable. I really don't like those huge guys you can only hit in the back.
I don't think they're going to have to deal with cobbling together four different games and having them run on a new and entirely different platform than what they were written for, so I'm going to have faith they'll get it right.
Also, I come primarily for the Halo campaign. Multiplayer is an afterthought in my book. So, yes I will take the plunge early on.
I, too figured Destiny or Dragon Age to take the top spot, but since I can't get DA:I to run without crashing on my PC and Destiny was decidedly less immersive than advertised, a dark horse and a console port of a game from 2012 are currently tied for my GOTY.