The Connexions platform has been around for a while now, and as I recall students whose classes used it were happy with it, from both a price and usability standpoint. Glad to see that the program is getting more ambitious -- the move ties in nicely with the backlash against Elsevier. The rise of open-source competitors to academic content providers seems like a huge win for students and institutions alike.
At my school, yep. There were two tracks: Physics for scientists and engineers, which used calculus, and physics for arts/humanities, which was "algebra based".
If the publishing industry has anyone with half a brain working for them, they should see themselves going the way of the music industry. They need to innovate fast. Open source books are only part of the problem (and by problem, I mean only their problem). It is becoming easier and easier to find torrents to download full color versions of many of the most popular textbooks.