Isilon is the business but I suspect it'll have to really solidify around 10-gig Ethernet to the desktop before it threatens traditional SAN configurations. It only supports IP protocols after all. I am a huge fan and I can't think of another clustered solution that has the robustness and ease of deployment/expansion than Isilon.
Rather strangely they are talking about Infinband to the desktop - now that I'm an evangelist for cat6a/cat7 I find that strange.