No site other then the creator of 'Auctioneer's site will have a release that is more up to date then his. He tries to keep control of his addon and only post it at his site. So if you have it, you know where his site is.
At this time, 1-9-07 he does not have a release version for patch 2.0. You can download his pre release version at his site. He is on Beta release auctioneerpack-3.9.0.1308, which works very nicly. Shortly he expects to release a Gamma version. Sometime after that a 'release' version will go out.
If you want to try another programe that does the same things just search for one at
http://wow.curse-gaming.com/en/