Consider this the official announcement: RPG Palace is converting software in a few days from IPB 2.1 to Drupal 6.19. This is more than just the forums; the entire site will be moved into Drupal, including existing news, tutorials, articles, and downloadable content.
Private messages will be lost. If you have any important information in your private messages, save it now.
Some users will need to re-upload avatars, though most avatars will transfer properly. Avatars on the new site must be under 160x160 in size; any existing avatars larger will not be imported (avatars which have been scaled down).
The entire process is expected to last about four hours. During that time, posting is allowed in the new shout box, on the IRC channel, and in a special group that will be deleted after the migration is finished.