This is going to be a short generation and I do not see 140M happening.
I honestly DO NOT think we will see console refreshes this time around, and instead will see 100% backwards compatible versions with stronger hardware. Developers will then code their software to run at X or Y depending on what model the owner has.
Microsoft is going to short circuit the generation one way or another depending on what happens this year. PS4 seriously has the XB1 beat to shit in terms of games this year, and i think this will be the PS4 peak year -- which will eat into XB1 sales. I also think we will see FW 3.5/4.0 launch by march and it will contain PS1 (and maybe PS2) FULL bc, 4K video support, and possibly the ability to remote play your PS3 on your PS4.