There are different levels of success, and different ways of measuring them... I wouldn't exactly call 40 mil as a flat number a "success," but I wouldn't call it a failure, either. It's just kinda... meh. I would call it a success if it retains the same market share vs the 3DS as the PSP held against the DS -- something like 33%. So if the 3DS sells 80 million lifetime, the Vita has to sell at least 40 million lifetime to be a market success in my opinion. If the 3DS sells 120 million, Vita has to sell 60 million, and so on.
To be a financial success, it basically just has to be profitable for Sony, but that's even harder to predict at this early stage.











