It's EASILY doable to level from revered to exalted in a day. You just need to do instances loaded with trash. Deadmines used to be awesome, then Devs decided to reduce the amount of trash.. yaaaay........
Don't quote me on this, but I think Shadowfang's the one that rewards you with the most rep. It has a lot of trash.
With a solid group, I think Throne of Tides farming could be some decent xp/hour grinding. It's a short instance with little to no trash.