I just happened to be looking at a widget on my Dashboard; it was misbehaving, so I decided to pres Cmnd-R to reload the widget. I was surprised to see that when I pressed the Cmnd key I could see the Windows Start menu pop up on the desktop underneath Dashboard. I can't say whether this behavior existed in earlier releases of this Beta, but I assume that Parallels shouldn't be intercepting keystrokes while the Dashboard is active.