if you´re an ISA administrator is much likely you heard about Thomas Shinder. He´s one of the masters of ISA/TMG firewall universe. Some of his contributions for ISA/TMG world are: www.isaserver.org web site, which contains a lot of articles about configuring, securing, administering, etc, ISA Firewall. Most of them are wrote by him, of course. He also have published a lots of books desmistifying the different ISA Firewall versions along the years.
Now, the mission he and other ISA/TMG firewall gurus have is to release Threat Management Gateway (TMG) Administrator´s Companion book(http://www.mstmgbook.org/).
I have great respect for Tom Shinder as he is a knowledgeable guy and for my surprise he mentioned my blog on his.
Thanks very much Tom, we´re exciting waiting for the TMG Book!