I hit 66 on my shaman and went into AV almost exclusively.

Hit 68 in AV and went and did a load of the starter quests in Northrend to gear up a bit more for BG's.
This will get you a level or 2, so you may only have to level 70-71 in AV with the lower XP levels.

From 71 - 80 I lived in AV with brief forays to try questing before going straight back in there.
If you are on a server and faction where you have no queue times for AV this works well.
(so long as you aren't getting hammered by the opposition every game).

Maybe it was because I was having fun - but 71-80 flew by for me in there.
(mind you having dinged 3 times in a day through AV alone sure helped -but that was a long day )