Patch 3.0.2 is going to bring us much of Wrath, without the new content. Specifically, we'll be getting the new spells and talents, which come out to a total class revamp for many classes. We'll also be getting a couple other fixes, like learnable mounts and mini-pets. And Tigole just confirmed today that among these will be a reduction in the amount of experience required to level between 60 and 70.
Levels 20–60 were sped up dramatically a little while ago, which I have been very much enjoying on my various alts. But the Outland levels have remained at the same rate as always. This isn't so much of an issue now, when 70 is the endgame, but of course we're getting another ten levels in LK, and trudging through Outland then will feel a lot like dragging yet another toon through Plaguelands now. (I know some of you like Plaguelands, but I just don't understand it.) So I'm glad this is coming a little sooner, so that hopefully I can have at least three 70s poised to go into Northrend instead of the two I have now.
What kind of a speed increase are we looking at? Well, the only hard numbers I've seen so far are 30% less XP required per level, and possibly 20% more XP given per mob, with no changes on quests. This is fairly substantial; I would be pleased.