Interesting rumor:
I was at a conference at [some place] on [doing something for people]. During lunch, I sat next to [Some very important guy who knows this stuff] and we got to discussing the sidekick.
He indicated that the sidekick III would be released in April of 2006. I asked him a few times for hints or details (believe me, I tried) but no luck.
The sender asked me to redact a lot of the info and hide his identity, but there you have it. April 2006. From someone who should know. [Thanks, Franco A. Wilcox of Madison, Wisconsin!]