I don't believe the 'always-on' bit for a second.
I don't think a company like Microsoft would deny themselves sales by implementing something like this.
With how often it gets mentioned in rumours some sort of "phone home" system for anti-piracy (or even anti-used games) seems more and more likely, though.
Plus you hear what developers say when asked about the next-generation and so much of it is having the experience integrated into online so they can have more direct communication with the consumer and all that stuff. As well as tie DLC/microtransactions and other additional revenue streams into games, even more so than they are now.