The DS wasn't disruptive (so the Vita can't be a counterattack to disruption), and the 3DS isn't upstreaming.
Vita is, in the end, business as usual for Sony. Sony doesn't generally "innovate", they take innovations introduces by others, and attempt to tweak it (usually resulting in just a "doubling" of the innovative thing). The only exception I can think of is Eyetoy.
So what is the Vita? A PSP with a boost in power, addition of touch controls x2 (touchscreen on front, touchpad on back), console-handheld connectivity (first seen on Gamecube/GBA, then Wii/DS), etc. It's entirely business-as-usual. And this is why it's a risky move for Sony - because there is no attempt to expand their market. What Sony needed to do was release something disruptive, because there hasn't been a real disruption in the handheld market - this would have forced Nintendo to respond.
Notice that Nintendo has pretty much paid no attention to the Vita?
The Vita is without a doubt a life-or-death kind of release for Sony - if it succeeds, Sony remains in the handheld space; if it fails, Sony will likely withdraw from it. But that's the only way in which the Vita resembles the Wii. And even in that respect, the contrast is great, as the Wii released to massive fanfare, disrupted the market, targetted the blue ocean, and has had clear and extensive impact on the industry. Vita, on the other hand, released with a whimper, and does anyone really believe that it'll do any of the other things the Wii did?
There was mention of social networking, etc. This is a dead end for the Vita, as it's something that is already done much more efficiently with smartphones, and since the primary target for Vita is technophiles, who almost certainly already have smartphones, they're setting themselves up for a fall.
This doesn't mean that Vita is doomed to failure. At the end of the day, the same rule applies as it did to every other system in history: it's all about the games. If Sony can get the right games onto the system, they'll do fine.