Honour is not going to be reset, but items at level 80 will be much more expensive. Still, if you are sitting on 70,000 honour when the expansion is released you will definitely have the advantage (I'm sure the honour cap will have to be raised to compensate for the price rise, as will the honour gain rate at 80).
More in-game models have been revamped.
Varimathras, grimmer than ever before
Alexstrasza, lookin' hot
I've been levelling a warrior recently. There is no possible way I will get her to level 70 (or even level 60) by the time that WotLK is released. But I can at least have fun in my spare time levelling her. Of course, it means that time is taken away from my Paladin, but I am having second thoughts about taking a Paladin to level 80. Mage, Rogue, Priest, Shaman and Death Knight will be enough. ;)
Gaiwyn of Proudmoore