Darn shame that this feature came out on April 1st.
We did not get what we wanted in the Resource Governor, so we had to implement our own tools to kill a query once it has run more than x amount of time or has an open transaction for more than y amount of time. This works all 365 days of the year!
I wish SQL Server had a SQL Judge, Jury and Cop rolled-into-one feature which would summarily execute a query once it has used up more than a set of defined resources. Very, very useful and needed for a live application that needs to be UP all the time without DBAs having to get paged.