In addition to my comment below, I agree with Erik.

On my "farming" toon, I have the current goal of maxing out my fishing skill. After the past two Saturday mornings of catching Golden Darters, I've gotten 365 skill.

On my main toon, it's maxing out the Outland factions before the patch. Just finished out Lower City (amazingly, it worked out that killing Murmur put me at 1/1000 exalted, and my Shouldergaurds of the Bold dropped), leaving only KoT and Thrallmar, both of which are just a couple instance runs from exalted. After that, if the patch still isn't out, I'll be running to pick up a dps set. If I finish that ... I dunno, guess I'll wear a wedding dress to tank Kara.

I could not agree more. For me re-rolling a characters always seams to re-ignite the wow flame. I have a 70 priest, lock, rogue. Now I am rolling a Druid (24 now) and I have to say the Druid is a little of each class I have rolled. My brother and I rolled Druids but have a rule, don't out level the other. We are going to level these chars all the way to 70. So far it has been a blast.

Yeah, I agree. Rep grinding, leveling professions, or one that my roommate thought of: mount collecting. You could also collect pets. Another that I like doing sometimes is running friend's alts through low level instances. Or one I tried recently was twinking. As you can see, I've gotten bored a lot.

I personally like my Tabard collection.