There are times when I'd like to communicate something to the Stack Overflow community but it doesn't fit a question.
Right now, I have the product of many answers (a bunch of code) I'd like to share back but can't.
If each user had a blog or wiki (or something) they could create articles / blogs on and then link the related SO questions to it. You could then add an icon to those questions to show there is also more expansive information available.
By linking to the questions, this means anyone could author articles addressing a question outside of the scope of the more simple Q/A scenario.
Of course, many people have blogs but they must link that in a not so immersive fashion and not everyone has a blog (and also many blogs are inadequate in displaying text from a coding viewpoint (e.g. formatting code). Folding such a mechanism into SO would open up all sorts of creative opportunities and make the site even more sticky for users.
I think it's a winner and I'd use it for sure.