Maybe this also happens (or happened?) to you: Outlook 2010 becoming unresponsive with the only way to get it going again is to kill the process and restart it.
In my case this was apparently caused by some Outlook OST/PSTcorruption that, in the end, is easy to fix: Outlook 2010 contains a nifty utility called SCANPST. You find this tool in the Outlook14 folder contained in your Microsoft Office folder. When called to the rescue, as it's name gives away, it will scan your PST or OST file and fix any problems in the file. You might need multiple passes to get rid of all corruption, but, in the end, I got my Outlook back and I am once again a happy camper!
With this problem fixed, I can start looking for my next favourite Outlook 2010 feature :-)