So basically what you are saying is this will be like any major patch where you WILL HAVE TO UPDATE most of your addons? It really isn't a big deal, most mod authors who are active are already pushing out updated versions of their addons for the test realms so that once the patch does go live they will be set to jet. Now I understand though you, just like me, might have that one or two addon(s) that havent been updated in awhile and the author has been MIA and it might possibly break, but it'll give you as well as me the chance to try new things. And with new things you might find a better addon who knows.
