Bumping folks off Wi-Fi network a "new" attack?: I've been hearing about this attack for at least 1 1/2 years. Deauthentication (and disassociation) requests aren't authenticated in the same way as the reverse process. Thus, a bunch of valid but inserted requests of this sort can provide Denial of Service (DoS).
The problem is at the MAC layer, if I recollect correctly: changes need to be made in the 802.11 MAC to prevent this kind of DoS. The paper that describes this problem appropriately notes that its contributions are more practical and advisory than new: they have a lengthy bibliography that credits previous reports.