I hear/read that the Consumer Electronics Association has come up with a standard to measure audio amplifiers, and that the FTC is about to adopt and mandate (recommend?) this standard. The "Standards" section of the Wikipedia article kind of allures to it but it seems to be under some flux at the moment and the references are a little sloppy. Still, the article is worth a read to understand the issues involved.

I think the CEA standard is:
http://www.ce.org/Standards/browseByCommittee_2624.asp


Axiom M80s + QS8s + VP180 <-- Pioneer VSX-1120-K <-- Squeezebox Touch / XBox360 / Oppo BDP-93