A chat room feature. Possibly the ability to make a private chatroom for a certain group or forum - maybe by giving a certain password.
A way for a moderator to nominate threads for a "classics" forum where interesting threads from all the forums would be copied. Would not be a lot in there to start with - but given time...
A way to put up links similar to what we had in Cubits - I don't want to have a lot of stickies clogging up the top of my forum. However, for people new to the type of plant my forum is about, I'd love to have a place for them to click on where I could post a lot of links for them to find more info. That way, they would know to come to ATP to my forum anytime they needed any info. I liked the "LINKS" feature of Cubits.