Yahoo!'s web 2.0 version of their PPC management software, aka Panama, is now going to be a mandatory switch for most advertisers by January 10, 2007. It was first released on October 17, 2005 to advertisers to try. Since then we have written about it a lot. New advertisers can now only sign up with the new panama system, as of last week. And now all (if not most) existing accounts with be migrated over by January 10, 2007.
Yahoo! has sent out a ton of literature on the new system. I received copies and originals of that information. It is organized very well and should have enough information for most advertisers. Yahoo! is looking for a smooth transition for both advertisers and on the tech side of things.
Update: Yahoo! called me to explain that although they do want to migrate everyone over by the end of Q1, these mandatory upgrade requirements are on a group by group basis. So for example, if you were invited to update on a specific date, you may have to upgrade the 10th. But if someone else was invited on a different date, they may have to upgrade on the 3rd. Etc...
Forum discussion at Search Engine Watch Forums.