I just spent several hours last night, researching on the web and trying different possible solutions, after updating Ubuntu and discovering, the next time I booted, that I had downgraded myself out of a critical desktop app (in my case, Netilla, used for remote logins). Aside from the mess created by Oracle, I'm sure Canonical has managed to alienate many users who were depending on java or its related plugin to run their apps, and found after updating that they no longer had any java at all.
This needs to be handled better, from a user's point of view, including:
- putting the known-downgrade in the user's face before updating
- informing the user of the possible choices
- offering to install a replacement
- allowing an easy way to keep some back-level packages, while updating others.
Perhaps most importantly, it would be nice to have some kind of "OS checkpoint" capability to allow for a rollback if the update fails.