YahooPete, the official Yahoo! Search Marketing representative, has posted in the various forums a reminder that Yahoo! will be automatically shortening your descriptions to the 70-character limit on June 20th.
If this sounds familiar, it should. Yahoo! has already prevented new ads from having a description longer than 70 characters on May 16, 2007. Although, it seemed then that the descriptions should have been automatically shortened - but I guess Yahoo! gave us more time.
This does not impact many international advertisers who are not yet on the new advertising platform, aka Panama.