Now how's that for a sensational headlline? And it's true. A paper released today presents an attack to reduce the computational complexity of brute forcing an AES-128 key to 2 by the power of 126.1 - which means such an attack would take only 30% of the time it would take to do the full 2 by the power of 128 exhaustive search. Similar reductions of about 2 bits are presented for AES-192 and AES-256.
Of course this attack doesn't have any practical impact - such an attack is still completely infeasible - but (as The H writes) it's a first dent in the full AES in other ten years of intensive crytanlysis.
In American slang "two bit" means insignificant - so I guess one could call this a two-bit attack.