There is already on the market some PCIe switches (like Accusys exasan) that are usable in a SAN infrastructure. As far as I know, those never really took off on the market so far, but they allow you to build a high speed SAN without fibre channel. You save a little bit on the fibre channel adapters and switches, but you still need all the components needed in a shared SAN (metadata servers, shared filesystem)
It would not be surprised to see the PCIe switches manufacturers coming up with a thunderbold switch using similar technologies, but it doesn’t mean the market will be there to back it. It will probably take a long time before those switches give you the flexibility and reliability of fibre channel switches.
If you want to build a SAN in August 2011, go fibre channel. And if your bandwidth requirements to your storage are so high, just use 2 8Gb fibre channel links from each hosts. You will need a lot of spindles to fill those links though.
BTW, Brocade just launched their 16Gb/s fibre channel switches, and the Qlogic ones are already announced.
Sebastien Bertrand
Ordigraphe Inc.
Toronto, Canada
https://www.ordigraphe.com