Syntheyes- http://www.ssontech.com/
Boujou 3D- http://www.2d3.com/
PFHoe- http://www.pfhoe.com/
The software you listed are simply a part of the system which they developed use, the tracking/scene analysis part of it. And you are right, that part of the software is not overly difficult to write, in fact you can throw together a Harris Corner detector + RANSAC to find correlation between the points and it'll do quite ok. In their case, they decided to use the Voodoo camera tracking system available here:
http://www.digilab.uni-hannover.de/docs/manual.html
which is comparable to the software you have listed
What I'm most interested in is the speed of processing their warps. From my experience of playing with ITK/VTK, generating non-rigid warps using b-spline, MFFD or any of the current algorithms takes a LONG time if you take the image content into account. I need to read the paper more carefully to find out.
Although this will be greatest interest to indie film and TV makers right now, selling to that market is a loss leader for most companies - the big bucks come from hobbyist consumers that want to shoot pictures or video but are happy to get an assist from the camera - hence the obsession with good autofocus on most camcorders, whereas pros are willing to pay a lot more for manual control of the focus plane. This is instant Win for whoever implements it first - it'll make consumers feel like pros, and it will save pros LOTS of money.