I dont think there is any inventory buildup from Q3 production. Manufacturing a CPU takes a quarter, as you know.
With regards to XP-inventories, I hope AMD shipped lower speedgrades (from inventories) this quarter than they put in from Q3-waferstarts. This implies little or no more Thoroughbred waferouts - which leaves AMD with two maturing processes for Barton and K8.
Therefore I doubt FAB30 currently is able to churn out more marketable parts than AMD ships in the strongest seasonal quarter.