I've never seen that particular unit before, but similar things have cropped up before. There are some constraints that limit how useful it is. The largest one is that it needs to be close to both your outdoor AC and your pool. Running really long pipes reduces the efficiency and the reliability fairly dramatically. Another is that your home AC has the most excess heat to give away in the middle of the summer, but most people aren't heating their pool at all during that part of the year. Meanwhile, in the spring and fall the home AC either isn't used much or isn't working nearly as hard, but that is when the pool needs to most heat.
There is also a mismatch between the amount of heat available and the amount of heat the pool needs. Most homes won't produce enough total excess heat to keep up with the full heat demands of the pool. A Typical home AC is around 40,000 to 60,000 BTUs, while a typical pool heatpump is 60,000 to 100,000. And remember the home AC won't be running at full capacity, or even close, during the spring and fall when you need the most heat for the pool. That means you need a conventional pool heater (of one kind or another) anyway, which pushes up to cost.
By the time you factor in the limitations, the initial costs, and the maintenance costs you aren't doing nearly as well as they imply. That is not to say that it is worthless. If you heat your pool during the middle of the summer as well as the spring and fall, and have an AC unit that is already near your pool equipment pad (or can build it that way in the first place) it is certainly worth looking into. That is exactly the situation that came up on the show, but it isn't all that common nation wide.
