I don't know how you can adjust the focal point from a flat display source. It is certainly tricky, but, possible. I mean, imagine your monitor as the surface of a mirror. The mirror is completely flat, but, it is able to reflect complete range of depths
of light source. Imagine we make that the same as monitor. That's what 3D is all about.
The stuff in the mirror certainly don't pop-out, but, they are clearly in their own focal point based on z-depth. This is what I am trying to propose. Imagine a monitor like mirror, but, just not your own reflection.
Maybe I should call it Mirror TV.
You should look at NVIDIA's 3D Vision; it produces the "3D into the screen" effect that you describe. The focal point effect is a different matter.
In some shooters that I've tried with 3D Vision, depth of field and 3D can combine nicely to achieve the effect of the water droplet example (e.g. around gun scopes, iron sights, close walls), but it only works where depth of field has been used/supplied
by the game. The system does not use plain depth information of objects to adjust their focus, as I think you're describing.