All of the workflow should happen inside one, morphing window. Instead
of popping up multiple sequential dialog boxes, just keep it in one
smooth flow.
I love that, much smoother, with less clutter. It also commits a user to the process, verses he or she cancelling because this is taking too long.
-1 to a preference, just ask for it when people first need it, and
remember it from then. This will be the U1 account in any event, the
user may well be signed into U1 already.
While I completely agree that it should be prompted and remembered, I would think that Launchpad's integration into the desktop would require some way of making changes, and selecting some preferences as to what you want your Launchpad account to be used for: U1, bugs, communications, etc.. ( I haven't played with U1 in Karmic though, so perhaps this is redundant?) Thinking about this more, a user's keychain would be fine, so I see your point.