my god, does anyone read the EULA and TOS of a software they install these days?
i suggest you go to
http://www.wow-europe.com/en/legal/eula.html and start reading.
section 4.a :
yes, the mods you developed for WoW belong to blizzard, you signed and agreed to it the second you installed the game. don't like it? remove the addon.
section 15
if you don't like the modification to the ToS, uninstall the game, you have a month.
i won't venture an opinion on what blizzard is doing, personally i don't care if the addons are free or not, but stop sprouting nonsense about your legal rights of ownership. you didn't develop a stand alone LUA application, you developed a modification based on WoW API, and according to your implied agreement with blizzard (consented the second you installed WoW and/or any of it's components) the modification itself doesn't belong to you as a commercial venture (intellectual properties are another matter, you can use it as a base of reference when you seek out employment for example, or use it freely to develop your own LUA based application).