1. Core Duo is Intel's new mobile platform. It's the follow-up to Centrino, and the actual CPU is the one that was codenamed Yonah. It's definitely x86.
2. I'd be very surprised. Core Duo is the mobile platform, and it won't make its way into many desktops. I was actually surprised to see it in the iMac, but then again, considering its design, the heat concerns of a mobile computer are at least somewhat applicable. Of course, Intel's future desktop processors are going to bear more resemblance to Yonah than to their previous Pentium 4's (or D's); it's a much more efficient design, and it's the beginning of what could be a very good year for Intel.
3. No
4. Entirely, by the end of 2006, according to Jobs' keynote.
If you're going to entirely refuse anything x86, by 2007, you probably won't be able to buy ANY new computer. I'd stop judging everything before you've even had a chance to try any of it. Apple wouldn't just fly to this decision, it would have to pass many meetings and go through plenty of testing and evaluating before they'd have even announced anything. OS X has been compiled for both platforms since its beginning. There must have been plenty of comparisons done. There may be reasons they're doing this that we, the consumers, do not know. Relax
