My bike's pretty damn heavy (12.5 kgs), but on the plus side, all the parts i have on it, i know that they won't implode if they take a bashing, whereas some of my weight-weenie counterparts have to give the bike a bit of a check over after a ride, and quite often, replace things every month because they keep breaking!
I did ride joe's dob before he left us for some sand, sun and camels, and i have to say, riding that was soooo easy! i can see why people go to the trouble of making it light!
It's not for me though, you just need to bulk up a bit
Matt