According to Ubisoft, they have two collector's editions prepared for release.
Both contain the game in a steel book as well as various in game items.
The one for US includes an additional USB with some goodies and a comic book.
The one for Europe includes a figurine and a soundtrack disc.
 
However, we have a thrid one here in Hong Kong. They call it the Limited Collector's Edition
We have the figurine, the game in normal casing and a flashlight (according to them a carbine torch or something like that). There are no bouns items though. But it's not all that expensive (at around $63 USD).
 I'm very disappointed that they didn't include the soundtrack though, since it's one of the major reasons why I decided to go for the LCE.
 
Anyways, I'm just wondering are there any more variants out there.

I believe there are also small differences between the PC and 360 versions of each package. I was looking at them, and quickly realized that I need a chart to figure out what I want. Oh, Ubisoft...