I just installed Office 2007 and started up the new Outlook. It prompted me to download WDS 3.0, so I did. I then restart and notice the new search textbox over next to my task tray icons. I click the magnifying glass, the large menu pops up, I click the X in the upper right corner. Boom, explorer.exe crashes. I start it back up, the textbox is now gone. I right click the magnifying glass icon in the task tray and shutdown WDS.
About 30 minutes later I try to maximize Outlook to view my emails. I receive the "Outlook isn't responding" bubble. I alt+ctrl+del and end Outlook.exe. After Outlook shuts down, I notice my CPU is still running at 100%. Hmmm. I glance down the list and explorer.exe is using 100%. For the next 5 minutes. I end explorer.exe and restart it. I restart Outlook. I pull up Outlook fine and shoot off an email. Meanwhile, I've left task manager up. Five minutes later, I glance over to it on my second monitor and notice the CPU is running at 100% again. I'm doing nothing. So I end explorer.exe again, sit there a few minutes and decide to uninstall WDS. After restarting explorer.exe, I open add/remove programs. I notice the task manager shift 100% cpu usage to explorer.exe for the next 5 minutes or so (even after add/remove has been opened and populated and is doing nothing). So I end explorer.exe and restart it yet again. I then uninstall WDS 3.0. Problem seems fixed so far.
Sidenote: When uninstalling WDS 3.0, I get this nice popup during the "Inspecting Current Configuration" step. It says "If Windows Desktop Search, these programs may not run properly." It then proceeds to list every program listed in add/remove programs, including Windows updates. Kinda overkill, eh ;)