Sometime between November 10th and 20th according to Empyrean:
I won't give specifics, but I am privy (pardon the pun) to release date info from separate sources from two of the three major carriers in Canada. I can officially say that the slider will be released by the end of the first week in November, so slightly sooner than the 10th estimate and way sooner than the 20th mentioned on CrackBerry's featured post.