The ALM Rangers publish a TFS Planning Guide which has a section on how to approach DR with TFS: http://vsarplanningguide.codeplex.com/
You probably should also consider designing a High Availability (HA) TFS deployment. Details of how to do this are in the TFS Installation Guide: http://www.microsoft.com/en-us/download/details.aspx?id=29035
In general though, at the core of TFS is a SQL Server, and all the best practices around HA SQL and DR for SQL apply here. Reconstructing an AT is relatively straightforward, and if you design a HA TFS deployment you will have multiple load-balanced AT's so if one fails the traffic just routes to the healthy AT(s).