by Jason Caldwell » June 20th, 2011, 3:43 am
Thanks for the excellent question.
I'm not aware of any way to accomplish this without breaking core functionality already built into WordPress. I can appreciate the need to do such a thing, I'm just not sure you'll get that accomplished with WordPress. Usernames are expected to be in a certain format ( i.e. lowercase alphanumerics, in some cases, particularly on a Multisite Network ), and attempting to change this would likely lead to larger issues.
That being said, you might try Elance.com or job.wordpress.net, to see if you can find a developer that is willing to hack the WordPress core, or build a special plugin for your specific needs.