I personally like it, but I do miss the quick routes that Quest Helper gives you. I may switch back when Cataclysm comes out.
So my improvements would be:
1) Give the quester a route to complete the quests as quickly as possible.
2) An "in flight timer" would be nice(will be pointless when Cata comes out since you can fly in the old world at somepoint).
3) An easy switch, to help toggle your quest tracking map without having to switch it off in the interface.