I don't think that Sony "won" E3, or that Microsoft lost. Instead, Sony called Microsoft's bluff. Stay with me here. All of the restrictions that Microsoft has put forth are enforced by software - they can all be pretty easily reverted. I'm willing to bet that Microsoft was really hoping that Sony would see this as the future of console gaming, and would follow their lead at E3. This way consumers would have been giv…
Can they though? Sure, it's pretty trivial to remove the code that enforces these restrictions, but I don't think it's Microsoft enforcing it.
Think about it - used games (mostly) go through authorized retailers, can only be sold once, where said retailers collect a cut, and Microsoft collects none. This isn't about Microsoft's bottom line, this is about the bottom line of GameStop, EA, Activision, etc.
There's no way MS would enforce this kind of DRM scheme on their own - they don't stand to benefit at all. If this was promised to retailers/publishers, they cannot just unilaterally walk away from it. Knowing no secret information, it strikes me that they may have legally painted themselves into a corner.