I do have a plan for my new Forsaken priest. You see, I never really leveled a priest properly. Lyl was leveled via Recruit-a-Friend to 60 in combination with Monera. It was fun, and at the time it was the right thing to do, since I had massive issues leveling a priest normally. Lots of horrible, horrible death, going oom, and generally not enjoying it.
I know they've vastly improved the leveling in Cat, and I've had a blast exploring bits and pieces of it Alliance-side. Hence, my priest plan rules...
1. Must get loremaster achieve/finish the zone story for every zone I do until I hit Outlands.
2. Must try leveling as disc and/or holy. Probably going Atonement smite. I'm thinking once I get dualspec I'll go disc smite/holy. In the long term getting more familiar with holy can only improve my healing skills.
3. No heirlooms. This is not a hardship since I'm on a different server from my heirlooms anyway.
4. No dungeons till 60. Then I can go dungeon-crazy if I want.
5. Occasional PVP is fine, but I must remember the point is to see the new questing content.
6. Only one gathering profession, since again, questing!
This toon isn't completely on her own, since I have a DK and a troll druid over there, but that's more to avoid the pain of not enough gold to train than anything else. I ended up with a Forsaken because a) I keep hearing how awesome the new Forsaken experience is, and b) I haven't really played one before.
Now, if you want to play along at home, here's a more general set of rules. The goal is TRY NEW STUFF!
1. Must level primarily in a way you haven't done before or in zones you haven't done since Cat hit.
2. Must level as a spec and/or class you haven't leveled before, or haven't leveled in a long time.
3. No heirlooms with XP gain.
4. Only one gathering profession.
See, simple enough, right?
Now if you want to make it more complicated, you can
1) run with a different UI layout from your main
2) see how far you can get leveling in only whites/greys
3) have the toon be completely self-sufficient, no influxes of cash from DKs or the like
4) go for ambassador!