A collector's edition hasn't yet been confirmed -- Naughty Dog is just testing the water to see if it would be viable. If you have a good idea for an Uncharted 2 collector's edition -- should one be made -- then leave a comment on this post, in case a Naughty Dog representative should come snooping round. Alternatively, feel free to twitter your idea and include the hashtag "#u2ce" in your tweet.
As for us, we'd love to see a boatload of behind the scenes content, an artbook, copy of the game script, a "How-to: The Perfect Half-Tuck" guide and a working replica of whatever magical treasures are found in the game. Nothing too extreme.