GoogleGuy did mention it in a recent post,
http://www.webmasterworld.com/forum3/22820.htm
and he did nuke this domain
www.hupo2003.com which was an expired pr7 a few days ago.
So be wary about paying big money for them.
Also all expired domains with a dmoz listing now gets automatically deleted so I think perhaps google and dmoz are sharing the same software and its quite possible that even if the newly expired domains still show pr on Google's toolbar it may be worthless for transferring page rank to other sites.