I'm also a little confused with the temps stated on the AMD site.
My motherboard supports monitoring of 2 temps - CPU and system. The CPU is pretty obvious, and I assume the system temp is the motherboard temp (measured at the hottest point ? - NB chip maybe ?)
My temps at my current OC (2650 GHz @ 1.41V) are:
CPU: 39C idle / 49C full load (both cores)
System: 28C idle / 30C full load
I am not using the stock HSF - decided to invest in a Zalman CNPS9500-LED Aero Flower. I don't know how much of a difference this actually makes, but probably no more than a 5C drop.
My case is a CoolerMaster Stacker, with plenty of ventilation, and current ambient temps are around 21C (will be closer to 30C during the summer).
General guidelines when overclocking are to try and keep the CPU temp around 50C max under full load. With your current temps, that would mean you have very little overhead for overclocking.
There are a number of factors that contribute to your system temps:
1. ambient temp
2. airflow in case
3. HSF - quality, fit, thermal grease used
I personally think your current temps are a little high, and would check the following to see if you can improve them:
1. airflow - make sure wiring is well located to allow air to flow from the front to the back of the case
2. HSF - if you used the stock HSF with the thermal pad supplied, then try refitting it with some thermal grease. Most ppl would admit that the thermal pad is not particularly good.
Note also that, over time (some weeks, depending on pc use), the thermal pad may 'bed in' and you may notice a drop in temps as excess thermal material is gradually forced out due to the pressure of the HSF retaining mechanism.
If you were to post your system specs (case, fans, other components), ambient room temps, etc., we could maybe help more.