EETtimes has an article about Data Center Convergence No longer a Pipe Dream with a quote from Renato Recio an IBM Distinguished Engineer.

"Somewhere between 50 and 70 percent of the Fortune 1000 companies are going to be building data centers in the next three years," said Renato Recio, a chief engineer for server networking at IBM Corp. "They are looking for technologies to make them more green, and this network convergence group has that value--this rings for customers," he said.
The moves fuel a broad industry drive to run networking, storage and clustering traffic over a single, mainstream pipe in tomorrow's data centers. The aim is to create one converged fabric, reducing the cost and power requirements of supporting today's multiple switches, adapter cards and cables.

The Green aspect comes from the power of the network chips.

A broad group of vendors announced their first products for Fibre Channel over 10-Gbit Ethernet last week. Separately, startup SolarFlare today is expected to announce a transceiver that can power 10-Gbit Ethernet up to 100 meters over copper on a single 65-nanometer CMOS chip that dissipates just 5.5 watts.
The work on the 10GBase-T standard for Ethernet over copper lines only indirectly fuels the network convergence. Its primary aim is to lower the cost of and expand the market for 10-Gbit Ethernet, which has been limited to expensive optical and short-reach copper cables to date.
Running 10-Gbit signals over copper typically has required multiple chips using as much as 12 W. The SolarFlare SFT 9001 transceiver could slash the power budget in half, but the company is still characterizing first silicon on the part, which it hopes to sample in May at less than $100.