Would it be possible to specify a full name in our profile. It would be nicer if my posts appeared as "Cédric Beust" instead of "cbeust".

I've been on the fence on that one - does anyone else have a preference?

I'd say leave it as an opt-in. Some people prefer usernames over real-names, while others like vladakk aren't a single person or prefer the veil of anonymity.

Agreed, don't force users to fill in these fields, but it would be nice if they could be honored by Sidewalk if the user filled them in.

Full names in sidewalk like "Cédric Beust (cbeust)" wouldn't hurt if it also allowed to use nickname only.