I've upgraded to Ubuntu 12.04 and did it offline using the alternative CD. I didn't look at the "packages to remove" section before clicking next - I've done Ubuntu upgrades many times and assumed it was just the normal set of obsolete library packages etc. But I do tend to watch the terminal text go by and see what it's doing, and I saw it removing a number of packages I wanted. I guess these are packages that aren't on the CD that can't co-exist with the new Ubuntu.
Anyway, I want to find which packages have been removed. So does the update log get saved somewhere?
Then I can start doing some grepping on it and then reinstall the packages I did want.