It will likely be another few months before you see any 2008 NEC offerings in either books or seminars. Until the final edition is published, nothing is for certain.
If you are asking that question of Mike Holt himself, you should be advised that he seldom participates in this Forum. You can find his schedule of seminars here: http://www.mikeholt.com/seminar.php?id=seminarabout
If you are asking that question of forum members who teach classes in your area, it would help if you told us where you lived (other than merely putting your zip code in your profile).
Most Seminars on the 2008 NEC will probably not start until October, atleast that is when NTT starts theirs and when I also will start my seminar schedule for the 2008 NEC.
I am sure this is similar for other educators as well.
The first IAEI section meeting that will cover the 08 NEC is in Anchorage, mid september 2008. I'll be there. Mikes seminars will start in the fall.
My first class will be in December, in Tacoma Washington.
I received word today that the Southern Section Meeting will also cover the 2008 NEC and will have 2008 NEC's available for purchase.
The Alabama Chapter will host the 79th annual Education Seminar and business meeting of the Southern Section of The International Association of Electrical Inspectors October 7-10, 2007. This meeting will be held at the Shoals Marriott Hotel & Conference Center in Florence Alabama.
I will be giving a Grounding and Bonding Seminar this Fall and will cover 2008 changes associated with Grounding and Bonding only.