Take a look at this document: http://www.vmware.com/files/pdf/view/VMware-stateless-virtual-desktops-ref-arch.pdf
This doc describes a View design that uses local SSD, and it works really, really well. I'm hosting about 70 destops on two Dell R710 hosts with less than $3,000 of redundant local SSD, and disk performance (and performance in general) is a non-issue.
I suspect a lot of SAN vendors wish this had never been published.
Geoff