Thanks for asking this question. I was curious about it too, but I think your situation might be normal. I'm a new owner (less than a week) of a 15" 2.4 and my fan speeds are always at ~ 2000 (sometimes 50-100 rpm less) even from when waking up from sleep and the case is 'cold'.
Mine gets pretty warm with normal use and 'hot' under heavy use (enough for me to be concerned and start looking at fan temps). I did some reading and I could be totally wrong, but I through I found that the fans didn't really kick up until the CPU was at 158f or higher and the limit on these CPU's was 225f (smoking hot).
I installed smc fan control, but being a noob thought if I didn't know what I was doing it would be more harm than good, so I removed it. I got paranoid and have thought something was wrong with the fans / temps since then, so it's sort of good to see other units are the same.
Regards,
Wayne