I use a MBP/15/2.33 with SmcFanControl 1.2.3 installed, and the fans' behaviour is really odd.
Sometimes, when I run parallels, the temp. reported by SFC would be ~60C and the fans would up their rpm to 4000-5000. Other times, when I really push the machine with matlab, and the temp. would reach 72-74C, the fans would stay at 2000 rpm, unless I will increase it manually.
Haven't seen fan speeds of 6000 rpm, though -- at most, I think, 5000.