ALNP has been used with SPDY for a while now. It one of the nice improvements that fell out of testing/iterating SPDY in public. The NPN approach was a bad idea since the client drove what got picked (With NPN, Server tells the client what other protocols it supports in the ServerHello and the client picks whatever it wants. ALNP reverses that.)
On a serious note: it's nice to see ALNP being used in HTTP/2