Without the casual market, which they have well and truly lost to smartphones, and since they will be ignored perpetually by third party developers and will therefore be nobody but a fanboys first choice, the WiiU will continue to follow the downward slope their home consoles have been on since the SNES (ignoring the Wii, which the WiiU is proving was a fluke). With a continual cannibalization of their own sales via 3DS versions (i.e Smash Brothers), a focus on just remaking their older games, whether blatantly (Wind Waker HD) or by pretending its new and expecting us to go along (Mario 3D HD), as well as a flat out refusal to innovate or do anything that might threaten their kiddy, safe image (and thereby grow their market), they will simply subsist on their fanboys. I predict 13.7 million at the most, with the likely outcome being 9 million or so - the equivalent of the Dreamcast or the Sega Saturn.
While beset a relatively unimpressive launch lineup and a continual wasting of all goodwill they have accrued, Microsoft will still be buoyed up by its hardware actually being current gen, and it therefore getting actual modern third party games. The shunning and third rate treatment of gamers and indie will bite it in the ass when those become the true focus of this generation, but until then, it should sell stably. It will likely outsell the Ps4 once Titanfall comes out, but this will be shortlived once the Ps4 version is announced. I'd estimate a total of 55-65 million consoles sold.
The PS4 will likely take an early lead off its preorders, and sell stably, buoyed by cultivating indie talent and using a series of smaller quality releases to eschew the traditional AAA drought that follows a consoles launch. A lower price than the Xbox One will mean it will consistently outsell it, barring the aforementioned Titanfall launch window. Following a price drop and the new Naughty Dog game in late 2014, the sales will escalate but steady themselves, with the stable level being about 18 million consoles sold a year (years down the track, mind - I don't expect it to hit that sort of stride til 2015). Barring a cannibalization of the market via game streaming services like Gaikai, I predict about 118 million sold.