jQuery is a default dependency for many WordPress blogs. Not all of those are run by folks who want/care about analytics.
Sure. I was assuming that culling to the "top million" would skew things in favor of GA. Clearly it didn't, but I was surprised. And you're probably right. All those Wordpress instances does drive a lot of the stats.
I had hoped at some point in the breakdown that they differentiated between Wordpress and.. everything else I guess.
Wordpress itself probably skewed the numbers significantly.