Sony announced at its Consumer Electronics Show that the PlayStation 4 had 4.2 million units sold so far. They also revealed that there will be a streaming service that will allow you to play PlayStation 1, 2, and 3 games.
In addition to the 4.2 million units sold, Sony also stated that they had sold over 10 million games so far.
Here is an exact quote from Sony about the PlayStation Now streaming service:
“The service, in the long-run. will provide Playstation owners with games they love from previous consoles from previous generations,” Andrew House, CEO of Sony Entertainment said at the conference. “It will also introduce the world of Playstation to non-console owners, via Sony smartphone and tablet devices. We are paving the way for gamers to play wherever, whenever.”
There will be a closed beta for the service this month, and it is scheduled to be released this summer.