There was a problem importing the global list: TF26204: The account you entered is not recognized.

If you got the error "There was a problem importing the global list: TF26204: The account
you entered is not recognized." while trying to import a global list file then probably one of the items in the lists contain backslash and TFS considers this value as a user name... I got this while entering the value 800\40. Funny!

Deleting work item in TFS 2010

After the release of TFS 2010 power tools I have noticed that the command destroywi that is used for deleting work items was removed. Searching the Visual Studio installation directory I found a new command line utility called witadmin.exe. This new tool hosts all the known work item management commands like import, export... To delete work items you use the same command as in the power tools with the work items id as a parameter:
Example: witadmin destroywi 10