I am having great fun in Cata leveling, Harrison Jones in Uldum is just awesome and very very well put together.
One thing that does bug me a bit though is the total lack of decent caster druid leathers you get from big quest rewards or dungeons. In the past this wasn't an issue as you could just collect whatever cloth bits came along and round out with leather when you found it.
But with the Leather Specialisation skill if you pick up cloth and do not go all leather you take a fairly hefty hit on intellect to do it. While leveling it isn't so much of an issue but I can see this being a bit of a pain when I am gearing up to raid in Heroics.