I would like to see people post a bit about their character, although I am not sure we should require specific information or that we should make it mandatory.
What I find of benefit of an IC introduction is that it helps existing players when they first "meet" you. Role-play is just like meeting and interacting with people in real life. Our first impression of a person will, for ill or good, form the basis of our feelings and reactions toward that person.
Giving a brief description of your character in an IC introduction, both of their physical appearance and their background gives other players a base upon which to craft their reactions and responses....food for thought, if you will.
To me the foundation of good role-play is where the individuals who are involved, offer cues that the other person or persons can use to respond. When I met a person face to face, I can hear inflection of voice, I can see facial expressions and the way a person holds his body. I can see clothing and jewerly. I can touch a hand to see if its warm, or cold, dry or clammy. All these are cues that I can use to form an appropriate response to that person when they make a comment or ask a question.
In role-play, we are dependent upon the person to give us these cues. It is very difficult, if no clues are given by one player for another player to do more than just respond to the comment or question. While I have no issue with a few one or two line responses, when that is all makes up an RP, it makes for dull reading and for me, eventually lack of interest in participating in the RP.
I would hope that it would be the goal of all participants to make interaction between their characters and others as easy as possible. Good role-play isn't in someone's ability to write a well written post. It's the ability to give cues and to take cues from others to let the RP develop in ways that the participants never envisioned.
Not to say that I have any issues with what is commonly called "closed" role-play where the outcome is pre-determined from the beginning by the participants. But when you have an open RP and one person consistantly ignores the direction of where the RP is heading because its not what they might have initially envisioned, it can often lead to a stiff and artificial feeling piece of RP.
And now that I have throughly gotten off the subject, I'll shut up *grins*