Ubunto Dapper Drake is now UVF:
UVF - The Upstream Version Freeze
The Upstream Version Freeze is the point in the development cycle when Ubuntu stops accepting new upstream versions of software or packages. This allows the Ubuntu developers time to stabilize the current software in Ubuntu and helps avoid introducing new bugs. You can find out a bit more about this milestone at UpstreamVersionFreeze.
More informations and complete improvement list available on the official wiki.
Releases as ISO and Bittorrent: