“One size fits all” doesn’t work for Ethernet, but this proliferation of speed options sounds like trouble without automatic capability negotiation. It’s nice to have options, but the IEEE must remain focused on interoperability and rein in the interests of the various companies proposing next-generation Ethernet technologies.
iSCSI is an excellent choice in situations where Fibre Channel investment is nonexistent or badly in need of wholesale upgrade. FCoE, on the other hand, is likely to take over in high-end enterprise shops. It is relentlessly promoted by major vendors, and it seems that they will force the upgrade eventually.