My predictions:
PS4 - 110 million
Mii - 100 million
NeXtbox - 85 million
3DS - 105 million
PSP 2 - 20 million
Concerning Sony, they have learned their lesson and will get back to what made them great in the PS1 era. Their console along with being a multimedia, multi-use device will have a resurgence of platformers (Remember JaK and Dexter and Crash Bandicoot?) , unrivaled 2nd party software, the best 3rd party software, and must have JRPGs such as a remake of Final Fantasy VII. Furthermore, the Move will convert over to the PS4 and by this time it will have a sizeable following due to a couple blockbuster pieces of software towards the end of the 7th generation.
Nintendo will not have it easy and will fight for every single console sold. Both Sony and Microsoft will be in their Blue Ocean fishing for their customers. Nintendo will garner a respectable 2nd place because with the 3DS it acquired quite a few 3rd party developers to complement it's unrivaled 1st party software. However, due to Nintendo downplaying online gaming and still thinking of multiplayer as what occurs in the living room, your FPS, sports, and MMORPG gamers will choose either the PS4 or NeXtBox.
Microsoft will be last next generation because it finished as the hub for the latest Call of Duty 2K"fill in the year" series. Call of Duty by this time will have already gone the way of the Tony Hawk series early on into the 8th generation. Unable to compensate for the loss of Call of Duty, the NeXtbox will have become a nostalgic machine where it is known for up to over 10 Halo games, 9 Gears of War games, 7 Assassin's Creed games, 5 Fable games, and the rest 3rd party shared with the PS4. Microsoft not developing strong 1st party software, 2nd party software, and the implosion of the Call of Duty series are the main reasons why the NeXtbox will come in last.
Regarding Kinect, it will still be around but nowhere to the extent of the Sony Move or Mii. With only one blockbuster title towards the end of the 7th generation, Microsoft will keep Kinect on life support via hundred dollar million ad campaigns touting shovelware and a couple of decent games every holiday season. It will sell, but nothing to the extent of Move or the 4 million it sold when it first came out.
The 3DS will put up a respectable showing, but it will not be another DS saleswise. Smart phone gaming this generation is ubiquitous and cheap with the most expensive smart phone games coming in at the $15-20 price range. Nintendo unable to lower the cost of their 3DS games, unable to match the graphics of smart phone games, and unable to match the innovation of smart phone games will sell mainly to diehard ex-DS users, which will be enough for 105 million, but nowhere near the 120 million plus the DS did before.
Sony with the failure of the PSP2 will call it quits with hand-helds. Sony prizing technological prowess and software touting that prowess will fail even more than the 3DS in countering the cheaper, higher graphics quality, and more ubiquitous smart phone games. Furthermore, the entry level price point of the PSP2 above $200 dollars, $35-50 softwar, and released well after the 3DS takes up the lion's share of the traditional hand-held market means the end of Sony's adventure in hand-held gaming.
