Yep, Barton in late Q1 through Q4 to allow Opteron/Hammer to ramp up. Barton will become the flagship for the Athlon XP line and filter down through existing clockspeeds (will appear at higher clockspeeds first), eventually replacing all T-breds, and remaining Pals and T-birds. The current T-bred core will eventually become the basis for the Duron line, which isn't a far cry considering a 1700+ and 1800+ T-breds carry value prices even today.
Chiz
Edit: Basically means Socket A will be alive and well for a year at least. My guess is that AMD will have some trouble ramping up to Opteron/Hammer (unfortunately for AMD, thats been their MO lately), and will end up having to squeeze every mhz out of Barton. Without knowing the launch specs of the first Hammer chips, the first ones may not command a performance increase proportionate to the increase in costs for a new Hammer system.