A lot of times when TDP is stated, this is short for TDP(max), and in this case, it does mean the maximum power the chip will consume.
In other cases, they are talking about the TDP "envelope" - the maximum dissipation for a package/architecture/etc.
This is something you've made up yourself. TDP "max" or TDP "envelope", they still usually aren't applicable to specific products. On these boards, as well as most others, it doesn't matter how many times the term TDP is explained, it still doesn't sink in.
Thermal Design Power is exactly what it sounds like. It's a figure used in the design of products such as motherboards, CPU coolers and the likes. Example from the URL in the original post:
Athlon64 X2 5000+ (2.6GHz) = 89W TDP
Athlon64 X2 3800+ (2.0GHz) = 89W TDP
Does it make any sense that these two CPUs manufactured on the same process and running on the same voltage (atleast it won't be higher on the 3800+) are outputting the same amount of heat? Nope. The 89W figure is simply given to other manufacturers so that they can verify that the line (3800+ to 5000+) will function correctly on their hardware.
In this case, the 5000+ might not even use 89W. It might use 50W, for all we know. The ONLY thing we know is that neither of these CPUs uses more than 89W. Common sense also tells us that the 3800+ won't be near the 89W ceiling.
For this new EE range of AMD processors, it seems as if AMD has chosen to have two different TDPs (35W and 65W). This also makes it easy for companies to support some of the line up. Just as in the previous example, it is evident that the X2 4800+ 65W and the X2 4000+ 65W don't output equal amounts of heat in the real world.
Another example: My brother's Sempron 2800+ rated at 62W TDP is considerably cooler running than my old AthlonXP-M 2600+ 47W. Again, the Sempron is very far from the 62W roof.
When are people going to stop using TDP to draw flawed conclusions? At best, it gives a rough indication of what to expect.
The Pentium M CPU has a TDP of 25w, but it is actually higher than that under load. Having said that, a laptop running on battery using the Pentium M typically lasts longer than a Turion 64 laptop with similar components.
Again: That number is for the whole Pentium-M line (actually 27W) and as far as I know, no P-M has really been that power hungry in reality. For example, my P-M Dothan 1.7GHz seems to output around 17W stock. Other measurements done on Pentium-M systems show the same thing.