While I was trying out the new 10 day free trial of Wrath of the Lich King that Blizzard offers, I was disappointed to find out that I could not level past 70 with just the trial. That didn't mean I can't still do the quests, though. That means you can reap the quest rewards that the Northrend quests give you and not level!
I know it isn't a great exploit, but I wanted to share with the community. Thanks!