Deneb high MHz/launch is a complete rumor at this point. HKEPC is definitely much more credible than majority of rumor sites that take a word and run a fully blown story on it, and they do always have at least something credible to base their data on. However, although it is definitely a model on the expected list, whether and when it comes depends on so much that none could predict its time-to-market, unless and until after the model is validated and supported by MB MFGs. Even then, it'll depend on the market at the point of its introduction, as does any SKU. The preliminary news is better than the +100MHz model they expected to launch priorly though. I'm certainly interested in the voltage for these parts.
Deneb as X2 with huge L3 cache per core is definitely on but I'm not sure of any dates/frequencies. 85W TDP is also the last we heard. I was expecting 2.7-2.9GHz though, so that was a surprise. Deneb in a 2 core form with 6MB L3 should perform quite a bit better than Deneb 4 core with the 6MB L3, simply due to doubling of cache per core. Power will always remain higher with such parts though due to cores still not being fused off but only being placed in a very low power state.
Every A64/K8 based rig at my office department and at the appartment I definitely had planned to upgrade with Callisto.. if it came at lower MHz. Office/home don't require such speed parts. High MHz means higher power/cost, roughly at the lower end of the Heka spectrum. I'd be immediately interested if they shipped some 2.5-2.7GHz Callisto models but that seems unlikely. I hope they keep the pricing structure similar to what they did with Agena based models, which would make Callisto a very clever buy.
If AMD can get their full lineup (largest volume is sub $200) out quick and clean, they'll do very well in the market for 2009. Even Socket AM2 MB MFGs are now officially supporting AM3 CPUs, which forms the largest AMD consumer base at present. Deneb 8xx, Propus, Heka, Callisto, Regor, all would form exceptional value offerings. The race is on.