Lately, we have been going back and trying to get them for titles, mounts, and just the general satisfaction of having them done. I'm not finding them as annoying as I previously did. I've also noticed that like me, most of my friends are also going back and getting as many MoP achievements done as they can. I love doing this because this allows me to focus on the new content that comes out without having to sweat about going back to the old world.
2. Pet Battles
I'm pretty behind on this, and I need to focus on this in the upcoming weeks. My goal was to have at least every mini pet to level 10 before WoD. I also have all the wild mini pets already caught, but if someone doesn't, this could be a fun thing to do, if you like that sort of thing.
3. Old Raids
There is always someone out there who is looking to get that certain tier set or even that one perfect piece to complete their transmog. Not to mention some of the really awesome mounts that have a chance to drop. While we have a schedule of what we run weekly - ICC, Ulduar, Firelands, sometimes Dragon Soul, a few weeks back I decided to spice things up with a naked Molten Core run. It was really fun, and we plan to eventually go back and continue on with Blackwing Lair!