Interesting stats (I liked your previous ones too).
One comment I would make is to suggest you avoid 3D graphs and pie charts. You'll notice that the depth increases the total apparent area given to BB/WebCT and Moodle, while the tilted perspective makes Sakai's share even smaller to the casual observer.
Since the numbers support Moodle anyway, you wouldn't want to be accused of fudging them with misleading graphics.