That is just the placeholder title IMDB uses. Nothing has been announced yet.

Rise of the Lich King is the title of a book by the way. If the movie is going to use this title then it's probably going to be based on the book.

I seriously don't think this is going to be the final title, seeing how the movie is due 2012 and by that time all the Lich King hype should already have died down. (Unless Icecrown Citadel is merely a setback!)

Laputa