If it were up to me I'd have so say probably not. You can have too many smilies IMHO and I think we have a good sensible balance. Not my call though, it's Rob's.
I would like a smiley for every imaginable emotion, no matter how esoteric, and then I want a symbol for every possible object or thing in the whole world, so that we wouldn't have to use anymore those pesky words with their deplorable and uncontrollable connotations and their hidden meanings like trapdoors etched in invisible ink.