When I began work, programmers typed their resumes on paper and mailed them (in trucks!) to prospective employers. Once there, the resumes were read (or at least skimmed) by a human being before being handed up to managers. In those days our online persona (such as they were) were usually separate and distinct from our real self. There were individuals who piloted on-line persona with their True Names and built a personal branding on that basis. They were rare, but it changed over time. There have been a lot of incremental changes, with job sites, personal web pages, and ultimately LinkedIn.
I think that if I were beginning today, trying to build a working reputation as a programmer, I'd do it with my True Name. There's an old saying from business that "every customer contact is a sales opportunity." In the web, as we grow, learn, and network, every contact is an opportunity.
As you build points and badges at programmer's forums, you build a rep. It's probably better do start that now under a True Name.
How you integrate that, or separate that, from a social persona on Facebook or something ... that might be a harder problem. Luckily, I'm too old to worry about it.