Miz is fine. A lot of people overreacted to some stuff they heard on the internet, which was probably an exaggeration anyway. Don't get me wrong, he did drop R-Truth, but I don't think they ever considered sandbagging him like a ton of people were saying. Miz has actually been doing pretty well for himself as of late, facing CM Punk in a one-on-one match and putting on a fine performance in the Elimination Chamber. Miz isn't a perfect main eventer, but he's working in his current role very well. He could be lifted back up to the WWE Championship with relative ease, if need be.
I envision Miz getting a few more holdover feuds with some fringe main event types and maybe even entering Money in the Bank again -- which he could very well win. The future is bright for Miz. He's a former WWE Champion, he's young, and he's improving. Like I said, he's not perfect, but he gets the job done. He's a good heel and he's great on the mic, if they build around that alone they can get him to go places. I can see him winning the WWE Championship again this year, maybe even the World Heavyweight Championship on Smackdown -- they just need to get past the WrestleMania stretch.