dons:
So after some nudging from Rob, and Spencer, I added proper state logging to xmonad. If you set 'logging = True' xmonad will print its internal state to stdout on each state change.
Then, using an external client, you can parse this info (the full state of the window manager!) and render it however you want. One use is to pretty print the workspace info into dzen, as if we had a built in status bar.
There's a script in XMonadContrib now, scripts/xmonad-status.hs, which implements an example StackSet parser/pretty printer for status bars.
Screenshots of workspace statusbars:
Actually, the current xmonad-status.hs is more like: http://www.cse.unsw.edu.au/~dons/tmp/dons-dzen-status.png (just numeric tags, since I don't use string tags). -- Don