So, on a whim, I checked out the source code for www.google.com, to see what else they're up to. The source is minified and therefore hard to read, but one thing jumped out at me and was a surprise: Internet Explorer-specific CSS. Of course, it makes sense that they provide styles for all browsers, but I'm using Chrome.
|HTML source of google.com, using Chrome browser|
I'm sure there's a good reason -- probably, the overhead of browser sniffing outweighs the benefit of trimming unused styles. Just curious.