For example, to get to Czech Wikipedia from www.wikipedia.org, I have to roll over the top right corner? That's absolutely unusable, I would never think of that.
Even better, the smaller wikis have very little screen space, so it might be impossible to get to them! Great design.
And I was going to say something about no-www [0] compliance, but that's not from their design, apparently there are rewrite (or redirect) rules in place for it. Ah well.
Represent all the arguments:
[0] http://no-www.org [1] http://www.yes-www.org (apparently defunct) [2] http://www.www.extra-www.org/