So I tried to turn off the Go button in the UI, and it promptly crashed and vanished.
I haven't logged off and on to see if it will come back, but I don't see it listed in my Toolbars menu as something I can restart.
There certainly needs to be someplace I can show/hide the search box besides the search box itself. There should be a control panel applet or something for all the search deskbar options.

WDS 3.0 Beta 2 Desktop Search Box crash
M.D.A
Hello NetMage,
Your suggestion makes sense. I'll submit it to the rest of the team. As for hiding the search box, you can do so by right clicking in the deskbar, selecting Toolbars and then selecting or deselecting the Windows Search Deskbar.
Paul Nystrom - MSFT
Michael Herman - Parallelspace
Selecting Windows Search Deskbar re-showed the search box without the go button. Turning the Go Button back on crashed my desktop again, and then it restarted without the search box.
It's cool that most things survive the desktop crash in the tray these days...