- Firefox asked me whether I wanted to launch the 'apturl' tool. I accepted its suggestion.
- I got a dialog saying "This will enable the Canonical Partners repository". I'm pretty sure I already had it enabled, but sure, what the hell.
- I got the usual 'downloading updated package lists' dialog.
- I got an error dialog complaining that 'adobe-flashplugin' is a purely virtual package.
And that was that.
Guess it's back to trusty ol' tarballs.