There has been a couple of requests about the logic for determining the default work item query in the Pending Changes window in Visual Studio. Here is how it works.
In the Pending Changes window, the work item query uses an MRU list. In general, once a query is run in the work item channel, the last-run query for a team project becomes the default query for that team project in the work item channel.
Algorithm for determining the query for the work item channel in VS
Delete the following cache file to clear the MRU history:
C:\Documents and Settings\<YourUserName>\Local Settings\Application Data\Microsoft\Team Foundation\1.0\Cache\WorkItemHistory_<YourServerGUID>
C:\Documents and Settings\<YourUserName>\Local Settings\Application Data\Microsoft\Team Foundation\2.0\Cache\WorkItemHistory_<YourServerGUID>