This session is/was true to its title and definitely dove deep into Virtual SAN (VSAN). Due to the extreme nature of details, requirements, parameters, etc, I decided to conclude the live notes about 40 minutes into the presentation. With much respect for court reporters and typists, finishing out the slide notes would have been of no more value that practicing my typing skills.
VSAN looks promising and maturing as a solution. While the concept of metro stretched clusters sounds very intriguing, I believe it is only practical in the right use cases. My own environment, for example, involves significant writing with extended operations, which would not be feasible to replicate live. Local performance would suffer greatly while database crunching generated large amounts of data requiring acknowledgement from the remote site before proceeding.
On the other hand, if your environment is web-scale or low-write intensity, then VSAN stretched clusters may offer great value to you. As always, it depends.
The closing consideration is sheer cost of a VSAN solution. The “HY-4” recommended starting point retails around $10-15K per node (read: $40-60K for the HY-4). That is hardware only, so vSphere and VSAN licensing costs pile on top of that.
The beta preview with dedupe and erasure coding for space efficiency may take VSAN to the next level and make even its premium cost more palatable. IMO: external storage is still the path until this possibility brings down the cost (assuming capacity, not compute, is the limitation).