PS Move: "second de facto controller for the PS3"

That’s how Sony sees it. Or apparently, has seen it since “many many years ago”.
In fact, going by what President and Group CEO of Sony Entertainment Kaz Hirai said during an interview with Telegraph, the PlayStation Move controller (as well as 3D support for PS3) have been subject of internal discussions within Sony for that much (vaguely long) time. 

He also mentions “affordability” and the desire to “get it right the first time” as the reasons it took those “many many years” to get the PlayStation Move out of the R&D building. 
As for 3D, glasses-based set up is seen as the “optimum” solution in the situation we are today.

Huge quote time:

“Well, both 3D gaming and the PS Move were things we discussed many many years ago.

Two things come into play with every technology that we bring to the table. First, we want to make it as affordable as possible. Second we want to make sure that there’s a robust library for the console and the interface.

We also we want to make sure the technologies that we offer are a complete package from day one. We don’t want to be in a position where we’re having to come out with something like ‘PlayStation Move Plus’ two years from now. We may take more time introducing these new technologies but that’s because we want to make sure we get it right the first time. We don’t want to be first into the market if we’re faced with a situation where we have to make too many improvements down the line.

It’s the same thing with 3D gaming – offering that experience without glasses would be great for the PS3. But the situation we’re in today, glasses and a monitor is the optimum set up. Future technology may produce monitors which allow people to enjoy 3D entertainment without glasses but right now it’s not a very good user experience.

Affordability is a very important point too. In the States, the PS Move is around $49. That’s affordable and it’s in line with our strategy to make sure the PS Move becomes the second de facto controller for the PS3, next to the Dual Shock 3, and not one of these “nice-to-haves” which you’ll only use with a couple of games. We want to make it an integral part of the PlayStation 3 experience”