I've been using xmonad for 6 months now and i dont think i can ever go back a regular non-tiling window manager again, dual monitors with independant workspaces is just too sweet.
Win + w/e to switch focus between screens
Win + tab to cycle through windows
Win + 1-9 to switch between workspaces on active screen
Win + Shift + 1-9 to send active window to workspace of choice

It was a pretty steep learning curve at first since the config is written in haskell, but totally worth it.

You can have floating windows if you really want to, but who wants to drag around windows all the time ;)

Win2k source code was a leak, everything after that was PR.