I can see where you are coming from...
But haven't similar products to do what you are describing existed before? Doesn't Hitachi have their Unified Storage product (HUS VM)? It's just horribly expensive. Atlantis have something kind of similar, where is combines RAM and any backend storage (DAS, NAS, VSAN or PSAN) to produce an NFS share back to the hypervisor (and it gives absurd performance in some cases): http://www.atlantiscomputing.com/products/usx.
Also worth pointing out that one of the blogs asked why the limit on VSAN was 35 disks per node. From talking with the VMware guys, 35 disks is just what VSAN is certified for (it was originally only 8 disks and then 16 in the Beta), it's not an actual limit. Pretty sure VMware will turn around on a 1.1 or 1.2 release and have just certified a higher disk capacity. Plus I'm sure that limitation isn't a top priority for them at the moment, seeing as EMC already have ScaleIO which is hypvervisor agnostic and can grow to stupid sizes.