Well, they could just chug along and make just enough money to get by (which it seems they are). Minecraft alone (games + merchandise) is doing its part to make XB1 do well every quarter.
But like PS2 era.......Sonys outright success will cause Microsoft to jumpstart a new generation, and leave Sony in a no win scenario: Keep PS4 going for more profits and give MS more time to establish, or rush PS5 to match next Xbox....and cut PS4 legs short in doing so.
Nintendo is doing this......but did so way too soon IMO. Xbox One still has 3 years left before a new gen i think
EDIT: They have to start a new gen and start it right. Like the 360, you launch with the gamer in mind. You make different SKUs for options in tech and price. And you establish yourself before Sony (because we now know they can't launch head to head).
Older and wiser. Still bias and proud though ;)