Well, I already have too many groups, or at least, I can't see well who's online anymore having to scroll the list down to see my contacts. Also, and in general, the contact list, in my opinion, is organized in a bit messy way ... At least for people who have many contacts online, plus many groups.
Sometimes we make acquaintances with lots of people, not having necessarily to become friends with them, which means that their names could perhaps be hidden and, at the same time, always researchable and/or selectable.
Please think about this!
Ps: How can we send private messages offline to our contacts? "Like" button in the groups would be useful too...