You can see my leveling bumps tend to occur on weekends. I need to continue averaging just more than 3 levels per week to follow the fast pace. Two levels on one weekend morning are easy, but that consumes the Rested XP bonus. Reaching that third level relies on something more. That something extra was quality quest XP from Dungeoning, which happened a couple times, but isn't reliable. Uldaman has too many pre-instance quests that need lots of travel. Still, it's a goal.
I'm going to mention that I don't expect to upgrade to Burning Crusade quickly. I want to experience life as a level 60 for a bit of time. I doubt I can do any level 60 raiding, but I do want to re-run dungeons to complete my Lightforge set and upgrade the Soulforge pieces. I want to also build my PvP gear, but that might be tough at the bottom of a tier. I guess that means staying in Alterac Valley for some time.
Those are my current thoughts. Have you ever delayed adding your expansion?