If his name really is Steve Jobs, it would be wise to adopt the use of a middle initial, or at least make a remark acknowledging the coincidence in his profile 'about' page.
Otherwise, even if no one believes it is "the" Steve Jobs, people will have the impression he's a prankster playing off the famous Steve for attention or laughs. (That's what you usually get when someone adopts a famous person's name in a pseudonymous web forum.)
Of course, we have an rms here, and the intelligent folk of HN know it's not the king of open source. I understand why it might be a prudent factor in making ones decision when registering, but I don't see why we should be tossing around advice to other people on choosing their HN handle.
Of course, 'stevejobs' can ignore this advice. I'm just letting him know some people will take him less seriously if the name collision isn't resolved or explained. Usually, such pseudonyms are from pranksters.
I think Kevin Fischer's choice of the handle 'rms' for HN was unwise, as well. That he clarifies that he's not RMS on his profile mitigates the faux pas a little. But why squat on such a famous handle? If someone without the initials P.G. could beat PG to registration of the handle 'pg' on some new hacker/startup website, and then use that handle as their own, would doing so be a good idea?