It's just the way it works, Intel Pentium line dominated until AMD released the Athlon line, and they continued spanking them until Intel released the Core line, now it's gonna be a while before AMD shows something more powerful again...
AMD is not doomed, as long as they keep releasing cheaper CPUs they're gonna have enough market, because not everyone is a gamer, or a heavy multimedia user, etc. and many people have a short budget for a PC...