For the longest time, the people who qualified as net legends was pretty small, and pretty much universally agreed upon. Sure, each group had their own legends, as the open-source community has ESR, RMS, or Bruce Perens The Original Author of The Open-Source Definition (yes, I think that's his full name). Others, like Knuth seem to rise above any particular community.
Now, with blogs and maturity of open-source organizations, it seems that communities are getting smaller and therefore it takes less to become a luminary within any particular community. Strangely, it seems that luminary status is somewhat transitive. Joe might be the luminary in the Froboz community, which only has 5 members, but he's respected by luminaries of other, much larger, communities. Sorta like the Senators from Rhode Island.
I recently found the java.blog community and pretty quickly established that Brett Morgan and Russel Beattie are people to listen to. I'm not a part of the RSS community, but I seem to understand that Sam Ruby and Dave Winer are at least making a lot of noise.
Over in jakarta, even that small community is fragmented. The maven community listens to Jason van Zyl (jvz) while, once again, the gump community looks to Sam I think. James Strachan (jstrachan) crosses several communities both in and out of jakarta.
One thing to note, is most luminaries tend to be known by their logins, initials, or some handle. A few are known by their whole names. I'm certain that RMS knows he's a net legend, but do all net legends recognize their status? Do they realize the power they throw around, necessarily, whenever they make an idle comment?
Sorry, no links, excerpts or references. Just random thoughts.