Chrome is getting some new skins, the baseball one shown is pretty neat.
Likewise the baseball interface certainly looks kinda cool and different but it distracts so much from the contents in the viewport because the “chrome” (the user interface, that is) is too fancy. One can barely see/distinguish the navigation buttons and the address bar from the white line and the grass image is drawing too much attention. And sadly such issues are with most custom user interface designs that some amateurs create (look at Opera or Firefox themes/skins).
Of course everybody is free at installing the skin of their choice but whenever I’m on a computer of somebody that has such crap installed I don’t find my way because it’s all so cluttered.
Sometimes it’s better to not leave the user too many choices. Otherwise we end up with offenses like MySpace.
I agree, Stephan, with the possible exception of Firefox--I'm waiting the theme revamp in 3.7 eagerly.
Some of those themes are awful, but some of them are quite nice. I like the Zen and yellow sort of striped one.