I will only buy the special edition of games that include stuff that are worth-while, and i really like the game. Like the MGS4 Special Edition included some cool making-of videos, and a cool headset. Thats why i got it. I will definitely get the GoW3 special edition, if it includes GoW 1&2.
I dont usually think collector editions are worth it. I only have 1.. MGS4 Collectors Edition.
I may be getting the uncharted 2, and the Assassins Creed. Still waiting to see whats included in them.