Overall a fairly decent post, but I think it's not without issue, particularly when it comes to the list. If I were to list off the things I do or am Interested in doing, my sub-list would look something like this:
Leveling alts (currently in a bit of a lull waiting for 6.1 heirlooms, not a long term problem)
Organized raiding
Heroic dungeons (if they provided a challenge similar cata, that was fun)
challenge modes (I do these, but I'm really not such a fan of the time requirement attached to it that basically defines all success or failure, so I don't do them much)
brawler's guild (finished most of the bosses already, but the queue takes forever)
rep grinding (I'd do this if the rewards were better and if the only way to get rep wasn't grinding the same spot for hours on end)
Apexis daily (I'd do this if the rewards were decent for my class to begin with, but I've now mostly outgeared it because of organized raiding anyway)
Pet collecting, but not battles
Primary professions (yawn, just a chore)
Garrison Chores (yawn, just a chore)
Collecting transmog gear (I did this... now I'm out of bag space and can't do it. This leads to other problems, like making many many other tasks tedious because I have no bag space)
Collecting mounts (being a druid makes this mostly not terribly interesting because instant forms are largely better, especially since i can gather without dismounting or needing a garrison building)
Toy collection (I've gotten most of the toys that I find interesting)
So from that list, but there's a lot of problems with various things that I would do. My biggest interests, in order of interest:
Collecting transmog gear
Organized Raiding
Leveling alts
Collecting Pets
All have some downside at this point. Transmog gear has lead me to filling my bag space and now I only have 4 free bag slots (excepting the reagent bank), Organized raiding is 3 nights a week and I can't commit to more, Alts feel like I'm neglecting my main, and I've got a huge number of pets and the remaining ones are mostly large amounts of work.
Overall, it's not that I don't have anything to do, it's that I'm too limited in doing the things I want to do, particularly transmog gear which leads me to doing so many other things, like questing, old raids, new raids, pvp and so much more, but without space for the gear, I can't do that.