Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
As long as you are willing to pay the fare difference between Coach and Business Class -- and there is still an unsold seat in Business Class -- I'm sure that AA would be happy to take your money.
If you're asking about getting a free upgrade, well, anything is possible, but I would not hold my breath.