I was checking the safe boater's course website, and according to the information listed, the safe boater's online and video courses will still be available after January 1, 2007. From how I interpret the information, it appears that one may still take the online or video course and subsequent test that goes along with it in order to obtain a certificate after 1/1/07. However, upon course completion, the certificate that you obtain by passing one of these courses will serve as your admittance ticket to a proctored examination at the department of safety. So, it looks like people will have to take 2 tests in order to get their official safe boater's certificate.
Here is the website with the information.
http://www.boat-ed.com/nh/nh_internet.htm