Question: In terms of integrating Blender renders with existing photographs, is there a way to create a set of Blender mesh points using the parallax info between just a pair of stereo photographs?

I've gotten good at regular camera tracking with video, and also using BLAM for static images, but what I'd really like to do is take two very clear and stable stereo images and extract as many good 3D points from them as possible, without resorting to also videoing in order to reconstruct the scene.

Answer: 
Or you could try point cloud reconstruction software which are free to download using Visual SFM and Meshlab. There are a few tutorials on the subject on youtube. As the question you are asking will require substantial write up, it's best to point you to some tutorials.

I learn this in 3 hours last night. However you may need more than 2 images.

<https://www.youtube.com/watch?v=D6eqW6yk50k>
Yes, there is a way, because there is an image processing package called Hugin (available for free), with tutorials from <http://hugin.sourceforge.net/> which does exactly what you want. 

I have downloaded it and tried to do exactly what you wish, but I've not yet mastered Hugin. I do perceive that it might be more doable with some images than with others. I have it, I'm trying to learn it, but I have to say that for me, it's been more difficult than Blender. .

Tutorial link: <http://hugin.sourceforge.net/tutorials/perspective/>