I do not know how it will actually work, but I am actually excited to see what happens.
edit: actually, thinking about it now - I think this is where the always online requirement comes from. If i was implementing this feature, I would allow the console to install the game content and have it associated with a unique ID for that disc. But I would have to check with the servers to see if that specific disc ID was already used elsewhere. If this is correct, then I think the always-onlne "feature" could be relaxed in the case where there are no unchecked games installed. This is just pure speculation, however.