Cool idea.
I think it should definitely be anonymous on the front end, but everyone should post up what they get.
We do secret santa where I work every Christmas and while this is typically a lame attempt promote comradery, etc. most everyone that works there is pretty cool so it is fun to see what people give and get. Sometimes funny, sometimes sincere, sometimes lame.
I'd be down.
Edit: almost forgot. The other thing we do when putting our name in a hat is write down one or two (general) things we like. Might be too tough logistically here, but just a thought. Give the other person something to go off of. Can lead to some very funny and very thoughtful stuff.