Big changes are in the works so far as the next version of the forum's system goes. It appears as though most things will continue to look and act the way we've become accustomed since the move from YaBB SP to YaBB SE, but internally everything will be VERY different. I've been checking out the Alpha preview of the new system and most things seem to work much more quickly. For example, instead of it saying something like "Page created in 0.424 seconds" at the bottom of the most forum pages, the new system will more likely be saying "Page created in 0.042 seconds."
One of the big changes that you'll be seeing once the new system is installed will be in your profiles. The new system divides a profile into separate pages rather than having everything all on one page. There are different pages for "Account Settings" (name, language, e-mail, hide e-mail, secret question, answer, and current password), "Personal Settings" (gender, birthdate, location, time format, time offset, Web site title, Web site URL, ICQ, AIM, MSN, and YIM), "Forum Profile Settings" (personalized picture, I have my own pic, personal text, signature, ), "Theme Settings" (an entirely new section that will allow cousins to set theme preferences: show board descriptions inside boards, show child boards on every page in boards, don't show other user's avatars, and don't show other user's signatures), "Notification Settings" (set notification for forum announcements and first unread replys in topics you'd like to be notified of), and "Instant Message Settings" (the settings for which they're still working on).
So, don't be surprised one day in about a month or so to discover that the forum has once again undergone a metamorphosis.