Alabama Governor Riley signed a bill into law making Short Barreled Riffles and Shotguns legal to own. The law was signed on 4/14/2010 and becomes effective on 7/5/2010. If you have a NFA Gun Trust, there is nothing you need to do, to be able to purchase these items after 7/5/2010.
This also means if you are going to travel to Alabama, you can use a Form 20 to bring your SBR or SBS to Alabama after the law goes into effect.