I've been waiting for this . . . Thane has been watching Signing Time! videos for awhile now. They have really helped his communication in a bunch of ways and I can't speak more highly of any other videos. My friend Michelle on OMOM suggested them to me and following her advice was so worth it! Thane has motor planning problems with his speech, as well as being developmentally delayed. I would say he actually learned most of his early language, and we all learned our signs, from this series. Thane still loves to watch them, even if he knows most of the words and signs in all 15 of the DVDs we have (the whole first series, plus the practice time ones).
A new series is coming out next month, so I just pre-ordered. This is the third time I have pre-ordered from the company as I like to get them as soon as I can. I read about it on My Two Boys, where there is a Signing Time! giveaway.
Added note: If you order through My Two Boys, it doesn't cost you extra and you can help fund an adoption.