Next week we start testing 10Gb (10GbaseT) iSCSI attached to new imacs with Thunderbolt using MPIO to hit 30Gbits/sec back to storage. It's going to be AAAAAWesome. What's really cool is that the iSCSI driver enables Xsan, so it's all compatible.
Previous testing with a single 10GbaseT port showed we could go faster than Fibre Channel. I expect 3 10GbaseT ports will go much much faster!