I just found think link from the CBC website. Looks like the series will start up again June 7, 2007 on CBC Newsworld. The article makes the point that the series was shot in 'magnificant high definition'....but then they air it on CBC newsworld and not the CBC HD channel? I truly do hate CBC.
MJK, there's a fairly good discription at this link as well.
http://www.cbc.ca/documentaries/planetearth.html
For anyone that's been looking for the series on DVD, have you seen it anywhere in HD DVD or Blu-ray?