It just occured to me that 2013 is probably going to have ten nominally unique hardware platforms:
Nintendo: DS, Wii, 3DS, Wii U
Reasons for four platforms: DS & Wii are still probably a combined 40-60m software market this year as there are probably 10 million game purchasing DS users and 20 million game purchasing Wii users yet (who will combine to buy about two games this year on average). Why take that much money off the table? 3DS should also be a 50m+ software market this year, and Wii U will probably be a 20-50m software market this year.
Sony: PSP, PS3, Vita, PS4
Reasons for four platforms: Vita & PSP are tiny for software, and PS3 is now declining steadily but still a large software market - PS4 can offset some of the PS3 drop.
Microsoft: X360, Xbox 2013
Reasons for two platforms: X360 is a large but declining software market, and the new Xbox can help offset that.
X360 & PS3 are down 40% globally through mid-February 2013 vs. mid-Feb 2012 (and 2012 was down on 2011), so it does seem like new hardware is coming.
Question is how many systems will be on the market in 2014 and beyond. My guess is
2014: X360, Xbox 2013, PS3, Vita, PS4, Wii, 3DS, Wii U
2015: Xbox 2013, PS3, Vita, PS4, 3DS, Wii U
2016: Xbox 2013, PS4, PSP2, 3DS, Wii U, DS2
People are difficult to govern because they have too much knowledge.
When there are more laws, there are more criminals.
- Lao Tzu
