I think this article from THR must define bubble show as a show where no decision has been announced yet. The have Without a Trace and Cold Case at 50-50, with one likely to survive. Eleventh Hour is considered in more grave danger. Dollhouse is 50-50 in their bubble show guide.
Chuck? Slightly worse chance than Medium according to the story.
But most surprising to me was this:
Over at the CW, "Reaper" is gone, while the prospects for "Privileged" have improved, and the show is now considered for a possible midseason order.
If Privileged is ressurected, I predict that will completely change the tenor of Renew or Cancel posts for next year. I kind of hope that it happens so I can do the historical montage (set to "The Way We Were") of all the ways Bill came up with saying you'll never see a new Privileged again, ever.