teh thing with LUA is its a blank slate. it knows logic and some types but for the most part LUA is what you make of it.I remember that addon. It was useful but none of my guild would use it, despite all running Valithria Heroic 10 man. It was useful for Putricide and Lich King too. Unfortunately, they removed a key piece of data from the script's access, which rendered the addon useless.
My only concern is, I hated the LUA programming language, for some reason I couldn't get on with it at all. Neither did I like the accompanying XML programming required to create user interface gumps / "boxes".
i don't know if we will do ui modding and stuff like that but the cool thing about switching to it is once we've done with the npc scripts we can use it for all kinds of things.
we had no idea how to easily let people set up new attacks etc. it seems more reasonable when its like 'i can expose some interfaces for that and make all attacks lua scripts'. its something we can just DO in lua but not in the language we have right now. to get to that point would take a lot of development for the language just to support the features we'd need.