For the first time we're allowing developers who don't work at Facebook to develop applications just as if they were. That's a big deal because it means that all developers have a new way of doing business if they choose to take advantage of it. There are whole companies that are forming whose only product is a Facebook Platform application.
Sometimes laughing isn't the best judge of what's funny 'cause I think there's a lot of things that are really funny that don't make you laugh that don't make you physically audibly make a noise but is something that is much more powerful than that.