MY EXPERIENCE:
Sounds bizarre SKYBOY but the general answer is no...because upgrades are relatively easy to earn with AA miles (what the hell are they called again?) and are usually heaving with U/Gs in Business.
Having said that I did manage to get one at Xmas. The check-in girl at LHR was feeling merry...and very nice of her it was too.
So the answer is yes and no. Try - you have nothing to lose...