AnandTech has published updated Yonah benchmarks, which show that Yonah Core Duo 2.0 GHz performs very well, even against its desktop counterparts like the dual-core 2.0 GHz Athlon 64 X2 CPU (with 1 MB L2) in professional applications.
Some are also reporting that Yonah will appear in an iBook in January. As I don't feel that any iBook would get a dual-core chip, I surmised that either these predictions are wrong, the iBook would get the more expensive 2 MB single-core Yonah instead of the cheaper 1 MB L2 version, or else the roadmap was wrong. Now I'm thinking that unless the product is in fact a PowerBook, perhaps the last option was the correct one. Researching this further, I see that some are reporting that in fact the cheaper 1 MB single-core Yonah will be released in January too. If that is true, then it would be perfect for a Macworld iBook Yonah release.
If this Yonah iBook prediction does come true, one wonders what will happen with the rest of the laptop lines. It would be nice to see dual-core Yonah PowerBooks released at the same time too, preferably including a 13" model. Even if there are issues with compatibility with legacy code, Apple could always continue to sell one or two PowerPC models for those who need perfect PowerPC compatibility.