I have looked at Tintri off and on, have had a few conversations with a friend over there (who is probably reading this now, HI!). I still feel that the upcoming VVOL stuff will level the playing field from a Tintri UI/insight perspective. It sounds like a nice VDI box but outside of that niche I don't see it being a threat to any of the big players.
Per VDI it certainly would be nice to see some sort of standarization as to measuring the cost of VDI. all costs including servers, storage, hypervisors, OS licensing, support, anything else I forgot. Sadly it seems that every VDI cost analysis I have seen a vendor publish seems to have a unique perspective as to what they consider cost.
Re: short lived?
I have thrown a moderate-sized (250ish VMs) VDI implementation at Tintri along with some high-i/o servers running PostgreSQL, MySQL, and MS SQL, along with some application servers, and my impression is that Tintri is very good value for the money. In terms of usable capacity, the value is not stellar, but cost per IOPS is fantastic, and so is opex: assuming you have sufficient network connectivity and are otherwise set up for NFS storage, you can be running VM workloads on a Tintri within half an hour of unboxing it without the need for professional services.
Tintri may be a niche product, but they have successfully identified and addressed some of the main pain points with existing storage vendors: complexity, cost per i/o, and performance insight. You can certainly build an EMC or NetApp box that will drive the same performance, but it will definitely cost you a lot more. On the flip side, all you can do with a Tintri is run virtual machines, but sometimes that's enough.
(AC because my employer might not approve of me speaking "publicly" in favor of a vendor.)