Hmm... I had no idea of this, but in this case I also agree that it was a major step in the wrong direction...
But then again we have to consider that Distributed Computing is not what brings the big bucks to the GPUs department of AMD... it's the games, and the gamers who buy the GPUs. My guess is that double precision calculations might not be something truly necessary for games, so they left it out. That way theres more free space in the chip, for more streaming units! (Some models have >1000!)