Keith if you look at B2L's IDC numbers and the Sun slides, I think you can interpret their comments to mean x86 server sales grew by 160%. Now last year that was all Xeon32, but given the reported trends over the last couple of quarters (also from IDC), you can assume that most of the sales were Opterons.
I would estimate that they sold around 10K Opteron servers in the last quarter (see analysis on SI).