Re: The C2D [ramp] is the fastest in Intel's history.
>> Is product transition as well? :)
Yes. Take the case of the famous Northwood ramp (lauded by many as Intel's previous "fastest ramp ever"). Northwood first launched in January 2002. The crossover happened in about the 3rd quarter, though Intel continued making Willamette Celerons well into 2003.
Taking Intel's Core 2 ramp in contrast, the Xeon transition happened almost entirely last quarter, and the mobile cross-over happened last quarter as well. The desktop cross-over is scheduled in Q3, which is about the same time it took Northwood on the desktop. Although, the complete transition is likely to happen even faster, given the E4000, E2000, and Celeron 400 lines that will be ramping sharply in mid-year.