I'd suggest doing dailies and working on any professions that aren't 350 since the new recipes will start around 350. Gathering professions should be maxed out so you can be ahead of the curve and they cost you nothing. Another thing would be to complete as many level 70 group quests as you can and sit on them in completed state so you can turn them in for a quick boost of XP after you install the XPac. I wouldn't save dailies since you can always do them again, but some of those big chains in SMV and Netherstorm have nice XP.

- Souca -