The nut is off of course and the 'nut-end' rubber bushing is out, but the bolt almost feels 'locked in' place; it turns but - I suspect it is held by the rubber bushing a bit but can't seem to get it to move.
I ran into a similar thing when working to remove one of the rear control arms. Bolt had rusted to the rubber bushing's inner sleeve. The pic doesn't show it very well, but both bolts are very nicely pitted due to corrosion. Definite candidates for replacement.
I ended up burning enough of the bushing away so that I could lock a set of vise-grips around the inner sleeve, and then persuaded the two to separate with a breaker bar. The fun part was finding a tension on the vise-grips that held the inner sleeve securely, but didn't compress it to the point of pinching the bolt even further. I'm looking forward to a repeat performance on the other side, and many encores when I do the front bushings... NOT.
I would have done just about anything for a cutting torch yesterday afternoon. Wanna see how much anti-seize I can slop in there when I put the new bolts in?
edit: awww crap.. image didn't take the first time.