I don't think they are converging at all.
The dSLR won't give you quality video and the HD video will not give you quality still photos.
Figure out which is most important to you.
The July 2009 issue of Popular Photography contains an article entitled "The Truth About DSLR Video" which discusses the advances and benefits of DSLR video. One filmmaker, currently shooting a feature length film with a Canon EOS 5D Mark II, going as far as saying that "the DSLR - not the video camera - is the future of independent cinema." Right? Wrong? Who knows, but certainly an interesting thought.