I think MLB and SS are the priorities, at least for the defense. I guess Irving isn't working out since even Brooking played ahead of him. A bigger type safety would be nice at SS who could help support the run a bit better.
A slot WR with more speed would be nice as well. If the o-line is healthy, then that is fine, but depth is not very good there, so in case more injuries, they could use better talent as backups.
The DL is not as good as it needs to be IMO. I am thinking if they keep Dumervil, they are better off using more a 3-4 defense. Most teams play both 3-4 and 4-3 during games, but I don't like the idea of Miller being wasted so much in pass coverage. He is by far their best pass rusher. Dumervil just isn't a guy that can be counted on by himself to generate a pass rush and probably would be better moving around in an OLB type position, sort of like the way the Steelers use their OLB's.