yes...

Are there smileys? I mean emoticons, like in forums.

Well, yes.

Yeah, except that you just added [[File:smiley.png|15px]]. :)

Which turns out to be a perfect smiley. :)

The point Yair is making (well from how I see it :-) ) is that it'd cool if typing :), :( , >:(, >:) :D, etc actually yielded emoticons as they in some chatrooms and fora. Btw, this is still awesome though! ^^

It would be pretty cool, but I could see it causing problems, and it's probably not practical. fr.wikt actually has emoticon templates, see fr:Category:Modèles d’émoticônes.

I would not oppose templates like possibly {{=D}} or {{;)}} which would return "standardized" smileys for anyone; but I'd also be inclined to choose my own emoticons when necessary.