I have never seen plastic bottles themselves as a green evil. They are very useful and imminently reusable... as long as you can convince people that they can refill them from the tap. It's really the insistence of the water industry that tap water is in some way impure and unhealthy that strikes me as the real problem (and, of course, it can be... but most places in the United States, it is fine).
I have mixed feelings about this line of paper water bottles. They look fantastic and they are certainly more green than plastic, but it still ties into the whole notion that you need to buy a new disposable bottle every time you go for a jog. I suspect they are marginally reusable, which off-sets it a bit, but I'll keep a single plastic water bottle washed and filled for months.
I'm doing a lot of needless hand wringing, though. These are very cool. I just wish people would stop gagging at the mere mention of tap water. I like tap water! It can be delicious!