I have a 3D camera, i can shoot 3D stills, is there a plug-in or some sort of post-production method to estimate the distance from the camera to every single object in the scene (maybe a pixel analysis) and then blur out the single pixels in base of the distance, to achieve true tilt-shift?
Given a stereo image pair you can estimate the depth to each point in the image (producing what is known as a depth map), from which you could stimulate the tilted plane of focus of a tilt shift lens.
There's no simple way to estimate the depth map but there are plenty academic papers on the subject. Likewise there's no simple way to simulate depth of field from a depth map though Photoshop's lens blur filter will get you close.
It would be much easier to use a tilt shift lens, however.
I'm not sure about the "tilt-shift" part but the first part of the question is feasible, see for example http://dplenticular.com/technology/creating-3d-images/ .
Obviously this works for getting a notion of the original depth, which one could use to create some post-production blurring, thus simulating a specific DOF (and also possibly tilted focal plane).