Ultimate Edition 2.0 just came out. You should be able to do an upgrade just from Synaptic as the repositories should now reflect the new edition. I don't use Ultimate Edition, but suspect that this should be the case.
See this thread about users who have upgraded from an earlier edition:
http://forumubuntusoftware.info/view...hp?f=45&t=1928
This thread discusses doing a remastersys and then re-installing as well. I would suggest that a fresh installation is better in most cases. Besides it is always good to have the UE 2.0 installation disk for fixing problems later. An upgrade does not give you this.
