No, it doesn't. That's the "BACK" button now. Which is a completely different thing from the up directory button, and serves a different function.

One of the things I dislike about Mac OS X is that it also doesn't have an up directory button. I can't fathom why they would remove it there, either.

Anyway, in both cases, the keyboard functionality is alt+uparrow (or in the case of the mac, swizzlestickcloverunpronounceablesymbol+uparrow). Those are the same as the up directory button.

On the mac, supposedly I can make a piece of applescript to turn that into a button. Haven't tried that yet. Would be nice if something like that could be done on Windows Explorer.