This group is dedicated to the discussion of the Yahoo! User Interface
That said, I would direct you to http://developer.yahoo.com
available APIs and tools are listed, and new offerings are announced.
I am not aware of anything for Y!Groups. By policy, we do not comment
on future plans.
Thanks for your interest and understanding,
> Is there an API yet for accessing the Yahoo Groups
> Calendar, or for that matter any part of Yahoo Groups?