Yeah, semi-auto rifles that look like AKs are currently ok without any special paperwork. Machine-guns (real AKs) need to have been registered since before 1986, have a $200 tax stamp, and the owner has to pass an extra background check, then they are legal, but there are so few of them around that the prices are silly. Probably $50,000+ if you can find one for sale.
And when Obama talks about "AK47s", he means the fake semi-auto versions that are no different than a million less mean-looking hunting rifles. It's all about appearance, not substance.