I see from Carswell's online catalogue that a new 7th edition of the the Canadian Guide to Uniform Legal Citation (the "McGill Guide") is due out on July 19, 2010.
There are separate records for what appears to be a softcover version ($50) or a hardcover version ($93) with no immediate indication of there being an online option.
I have long been critical of parts of the McGill Guide so it will be interesting to see what is new in the 7th edition.
I found with the 6th edition there were no good examples of citing to the Canadian Encyclopedic Digest or to your typical OBA or LSUC conference paper. One hopes the editors listened to my complaints.
I also hope they take a more permissive attitude towards neutral citation. I am a strong believer that citing a case with a neutral citation to only the neutral citation is sufficient, with there being no need to include parallel citations.