#0 - Nov. 30, 2006, 3:03 p.m.
Essentially, we don't want UI mods to make combat-sensitive decisions for players and as such, we've made some changes that block functionality that we feel is counter to the spirit of these philosophies. As such, addons and macros can't make decisions on who to target or what spells to cast.
That being said, our programmers have implemented a host of new functionality in order to allow many popular and benign UI mods to continue to function (once those mods are updated to take advantage of the new functionality), and will be providing some follow-up information on these forums as to how to take advantage of the new functionality.
Just to clarify, addons and macros will still be able to cast spells (with user interaction of course), they just won't be able to use logic to intelligently pick spells or targets.