There is no way next gen will match this gen in sales performances.
No single console will grab the grandma/soccer mum/kindergarten fanbase of the Wii.
Nintendo is simply out of the race.
And the 2 hardcore consoles (PS3/720) would probably sell an equal 10 mil or so a year. I doub't they will peak any further than 40 - 50 million by the end of next gen. Technology market has changed considerably in the last couple of years and tablets have overtaken consoles as the go to toy for casuals.
Similarly, I can't imagine any popular games selling COD / Halo levels like this gen. Most big hits will probably sell similar to what most bigs hits are performing currently, ie, 1.5 - 2.5 lifetime.








