A good write-up here in EE Times on the steps chip manufacturers are taking to improve their 10 GbE products, hopefully with an eye toward enhancing servers' ability to function in converged data environments.
A major hurdle is developing a system that supports both virtualization and TCP offload engines, which has become more complicated now that the industry is expecting to throw Fibre Channel over Ethernet (FCoE) into the mix.
One leader in the field is ServerEngines, which is nearing the release of a design featuring 5 GHz PCIe links with support for single-root virtualization (SR-IOV), which should boost throughput from the current 13 Gbps to near 20 Gbps. Multi-root IOV is also nearing completion, bringing up the possibility of servers sharing I/O resources on the network.
NetXen is also nearing a 5 GHz PCIe chip, most likely based on Intel 45 nm Nehalem processors. The company is talking about one-way throughput of 9 Gbps through 10G ports using VMware software.
Still unclear, though, is whether improved chip-level performance will cut the cost of 10 GbE connectivity. That may be something that only economies of scale can address.