These days I spend a large amount of time in TFS 2012.
In TFS 2008 and 2010 users could use the q.aspx page to run a query using WIQL as defined by the 2010 WIQL spec (http://msdn.microsoft.com/en-us/library/bb130306(v=vs.100).aspx). Ken O' Bonn has a great post on this at http://blogs.msdn.com/b/kenobonn/archive/2009/05/28/how-to-link-directly-to-tswa-2008-or-2010-beta1-work-items-or-queries.aspx
However in TFS 2012 the URLs for everything changed and I was unable to find any information on how to accomplish the same task. How can you provide a URL to users that queries for work items without writing and saving a query to the TFS server.
The key is I don't want to save a query to TFS.
So after some trial and error I found the way!
http://tfstest:8080/TPC1/project1/_workItems#_a=query&wiql=select id, [System.areapath] from workitems
The WIQL for 2012 is defined at http://msdn.microsoft.com/en-us/library/bb130306.aspx#language