IOS v12.4.11-XW8 has been posted for the UC520 on June 9, 2008.

Cisco Configuration Assistant 1.6 has been posted.

After a delay of what seemed to be forever, 4.2(7) for the UC520 has finally been posted for download!

Go here http://www.cisco.com/cgi-bin/tablebuild.pl/UC520 for all the goods.

Found this nugget of information on Cisco NetPro forum: The next CUE release for UC500 will be 3.0.3.1 which is planned to available the first week of March.