These stats and graphs are at least a bit misleading.
For the Firefox cross section they show
10.91 + 3.20 + 0.72 + 0.99 = 20.08 ?? It is in fact 15.82
Which explains my first question: Where is Firefox 3.6? I cannot believe ie6 is still "so big" and Firefox 3.6 has vanished. Which it hasn't. It clearly has ~ 4.26% or a bit less.
Kinda misleading info graphic