Here at work, a lot of people use the term "rock star" to denote someone of great skill or proficiency. For example. "He's a regular expressions rock star." or "She's an Oracle DBI rock star." It's considered high praise. I had never heard "rock star" used like that before. Maybe it's because so of them come from the East Coast.
It feels good when someone calls you a "rock star" (I was, briefly, the rock star of perl maps). I just wish we got groupies too.