CPU frequency does not down-clock when idle, Power waste or is this OK?

Question

I was browsing through the BSD sysctl's of OSX 10.6.2 today and noticed something I thought odd. Looking this up on different searches produced no useful results so I thought I'd ask here.
It seems that the MacBook late 2006 Core2Duo T7200 model has no cpu speed scaling. As far as I can tell, looking in the 'sysctl' output gave me these results:
sysctl -a |grep freq
hw.busfrequency = 664000000
hw.cpufrequency = 2000000000
hw.tbfrequency = 1000000000
hw.busfrequency: 664000000
hw.busfrequency_min: 664000000
hw.busfrequency_max: 664000000
hw.cpufrequency: 2000000000
hw.cpufrequency_min: 2000000000
hw.cpufrequency_max: 2000000000
hw.tbfrequency: 1000000000
What this shows, CPU frequency maximum minimum are both 2 GHz, bus max and min are also 664mhz. These should be able to change I would think.
(The "tbfrequency" value I believe is timer speed; 1gigahertz assures smooth media playback and interactivity. This is not the issue)
I was under the impression that Core 2 Duo's were supposed to have "SpeedStep", to make the cpu run slower to draw less power and generate less heat. On my desktop, this definitely works and I have measured it with my Kill-A-Watt meter. I would think the same happens with all cpus, so I wonder: In my macbook, is the lack of slowing down the CPU using more power than necessary?
(edited to add more detail)

Answer 1

I'm sure it's slightly less efficient. However, any CPU will still use a lot less power when there's less of a load (as you can see by running CPU-intensive tasks and watching the battery drain compared to when nothing is open).