Well, it depends on my current frame of mind. If I'm in a 'grass is greener' frame of mind, sell my 40d, 430ex, 24-60, 10-20 and 55-250 and buy a d700, 24-70 and a 70-200.
Alternatively I'm totally happy with my 40d so i'd buy a 5d2, sell the 24-60 and get a 24-70, sell the 10-20 and get a 17-40 and keep the 40d for the 55-250.