There is no advantage at all for pre-ordering the game now compared to pre-ordering it in 6 months or so. Might as well wait and see what the collectors/limited edition will have.
I'll do what I always do, laugh at the guys who pre-order half a year before it comes out, and then pre-order it the day before. I've never been let down with that method.
I also have a thread already http://www.gamesas.com/index.php?/topic/1165758-collectors-edition-or-normalstandard-edition... (First of its kind. :glare:)