I haven't actually encountered this myself, but according to mclasen and halfline, with plymouth < 0.8.8, there's no output when doing an offline package update, and this is the problem that https://admin.fedoraproject.org/updates/FEDORA-2012-16937/plymouth-0.8.8-1.fc18 was intended to fix. That update got held up because it causes some serious breakage, though, and now we're in freeze. So if we want to pull in an updated plymouth to fix the offline update output problem once the breakages are addressed, there would have to be an NTH or blocker bug to break the freeze. So I'm filing this bug on the offline update issue and nominating it for NTH.
Discussed at 2012-11-05 QA meeting acting as an NTH review meeting. Agreed it's now too late to be fiddling with code this fundamental, especially with the demonstrated possibility for breakage. Rejected as NTH for now. if we slip the release again and a fix for this is available, we could re-propose it.
*** This bug has been marked as a duplicate of bug 872886 ***