Nintendo: The Wii U will have been a moderate success (think Xbox 360 levels) and yet it will get more third party support than the Wii ever did. Casual games will never really take hold on the console like they did on the original Wii, so the Wii U resembled the N64 and GC more than it does its predecessor. The 3DS will still be going very strong and getting enormous amounts of support in terms of both core and casual games. Malstrom will continue to complain because that's what he does.
Sony: The PS3 could well be approaching 100 million by the end of the year, but realistically more like 85-90 million. Vita will have started to pick up and get some proper support to go along with the excellent technology. The PS4 will have been out since late 2013, will be a little more powerful than the Wii U with more RAM, a simpler architecture and more integrated motion control (though the gamepad will remain as the primary control method). Vita connectivity will be played up a lot and either the PS3 or PS4 will be bundled with the Vita, perhaps both.
The Last Guardian will finally be out (I wish), and the PS4 will have launched with a much stronger lineup than the PS3, though perhaps not as strong as the Wii U. Online will remain free with a premium service similar to PlayStation Plus available from PS4 launch.
Microsoft: Like the PS3, the Xbox 360 should be around 85, but I don't see the slight possibility of cracking seven figures that I do for the PS3, just because the trend is quite steeply downwards. Controversy time! Kinect will have gone the way of Sixaxis, still occasionally thrown into games, and even with some games designed around it, but not the be-all and end-all of control schemes that it was arguably intended to be. Nevertheless, a far more powerful version will have been included in the Outlook Box or BingBox or whatever they call their new system, and this will be more commonly used outside a motion controller similar to the Move or Wiimote. Smartglass will have fizzled out and been largely replaced by the new Microsoft handheld. The NextBox will have been launched around the same time as the PS4, and at a similar price level. It will lack the early third party exclusivity of the 360, but this will be partially improved by a larger first party range of developers.
Apple: Either they have a revolution like the original iPhone, or they start to crumble around this point.
PC: Bigger than ever before. Steam will be hitting 10 million concurrent users. Origin will be shut down for being unprofitable. Indie gaming will be in a new renaissance. Cheaper and cheaper components will mean that, once again, a gaming PC is cheaper than a console with better performance. By now, however, the consoles have begun to offer more unique experienced tied to gaming, so both forms of gaming will continue to exist.
Misc: Gabe Newell will still be fat, everyone will still hate Bobby Kotick, HL3 will have no release date, people finally start to forget about that god awful Cake is a Lie meme.