I've said I don't know what I think about it and I'm sure there are pros and cons, but I think one important benefit is that kids can watch the video over and over if they don't get it the first time. Parents can watch it as well in order to understand the way the material is taught to help their child. My kids have brought home homework that I did not understand because I did not learn math the same way. The math mountains with the little dots going up the side. The "sticks and circles" to show place value. So sometimes the kids are on their own. With a video, I can watch it so I understand how it's being taught. Is it homeschooling? I don't see how it's different than a parent assisting a child if they are stuck on their homework.
And the teachers DO interact with the kids on the material the next day, but not in a lecture-format. They can figure out which kids are stuggling and focus on them, and allow the rest of the class to move ahead or learn the topic more in depth. It's not like kids are doing everything on their own at home, like an on-line school. By taking the "lecture" out of it, it removes so much of what is wrong with the current system....for instance my DS having to sit everyday and listen to "what is 5+2" questions in a group when he is way beyond that and doesn't need to hear it over and over and over again.
For some subjects like English or Science, I don't think it would work as well. But I think it's probably fine for math.