So we all know that you stack 25 dailies for the start of MoP to gain an advantage - by the way you can have 25 quests in your log and WoW will automatically give you the pandaren starting quest and you have 26/25, so no need to abort one prior to MoP.
Now the interesting thing is, you should wisely chose which quest to take.
All profession quests will scale with your level - so take the cooking, fishing, jeweler dailies in origrimmar/stormwind and dalaran and turn them in later (for example when you do instances with friends first). They will then give most xp at lvl 89 of course.
You can use the teleport ring to teleport to dalaran for example and/or the guild stormwind/orgrimmar teleport tabard.
Good luck leveling
If you finde more quests that scale please share them here.
Proof for the cooking quest: http://imgur.com/l1w1y