We plan to publish our new Exchange 2013 SP1 servers (3 in DAG) outside corporate network using TMG 2010. I am looking for some guide how to do it in the proper way. What I found is little old and does not take into consideration Exchange 2013SP1
http://blogs.technet.com/b/exchange/archive/2012/11/21/publishing-exchange-server-2013-using-tmg.aspx
Any advice how to publish Exchange 2013 OWA using form-based authentication and how to use Kerberos Constrained Delegation?