Newegg is blowing out the 754 3200+ Venice chips ($36, free shipping and a flash drive), so maybe this will be useful to someone else. It's actually why I registered for the forum, I was puzzled by the high temp, 17C over ambient with a Thermalright XP-120 at idle, 27-28C over ambient under load (Prime95 stress test) with a Nexus 120 at full speed.
I'm still not sure how TDP relates to overclocking, but mine doesn't seem to overclock at all, on an 8KDA3J that had previously OC'd a Sempron 2800+ to 2.4GHz at the stock voltage. With this 3200+, windows was flaky at 2.4GHz, I didn't pursue any further. At the stock 2.2GHz it works fine, temperature stabilized around 28C over ambient after a few hours of Prime95.
EDIT: overclocks fine with one dimm, stable at 2.6GHz, stock voltage, haven't tried higher. In any case the overclocking problem was the mobo, not the cpu.
AMD64 TCaseMax - v1.19
CPU Information (CPU #1):
Standard CPUID: Family: F, Model: C, Stepping: 2
Extended CPUID: Family: F, Model: 2C, Stepping: 2
CPUID String: 20FC2
Processor APIC: 0
Processor: AMD Athlon 64 3200+ (Venice)
CPU Speed: 2210.08 (200.92 x 11.0)
Platform: Socket 754
Startup VCore: 1.400v
Maximum Case Temperature = 69C
TDP: 79.4 Watts