Edit: April Fools!
Hope you all had fun and we've restored all the deleted posts. :)
We have managed to get our hands on an alpha client for patch 5.4 and it has major changes for the User Interface. When we extracted the UI files as per usual, we discovered that all of the default Blizzard UI files are now swf and js files. Apparently they are switching to a flash based UI!
Here is a screenshot of the new addon folder:
(click image for full sized image)
We asked our contacts at Blizzard what was going on and they had this to say:
Originally Posted by Blizzard
We here at Blizzard have always been keenly aware of our addon community. We’ve noticed that addon creation has stagnated as of late so we wanted to do something to help revive the community. We looked around the gaming industry to see which games still have thriving UI communities and how they are maintaining their communities’ interest. The most novel approach we saw was Funcom’s The Secret World use of a Flash based UI, so we are going to try taking a page out of their book. We will be doing the actual WoW UI application in Java, to maintain cross-platform useability.
We hope that this will give the UI community a good shot in the arm. Going to a Flash based UI with Java will provide a lower entry barrier to new modders wanting to be able to write addons for WoW. Hopefully our addon author community will agree and embrace this opportunity to revive their existing addons and pursue new ideas.
When 5.4 is ready to go on the Public Test Realms, we will run a longer than usual test phase. We've been testing this in-house for some time now, but we realize this is quite the change. By running a longer than usual test phase it will allow for a thorough testing of the new default base UI. As well, this will help the authors who will have quite a lot of work to do in order to bring their addons into compliance with the new system.
We have uploaded the new dev kit in our Developer Utilities section so you guys can get a head start on converting your existing addons over to the new system. We will be updating it as any changes are made to those files. You can get it here.