While Raspberry Pi fans were told to expect a brand new board somewhere around 2017, it turns out that wasn't quite true. This is the Raspberry Pi 2 Model B: a substantial upgrade from the Model B+ that will go on sale later today for $35/25. The new board has some fundamental upgrades that could well warrant the upgrade for existing Raspberry Pi dabblers -- that is, if smaller wasn't better. Raspberry Pi Foundation lead Eben Upton told The Register that the new Model B "is a usable PC now." A fact borne out by official support for Windows 10.
"You could use a Raspberry Pi 1 as a PC but you had to say 'this is a great PC in so far as it cost me 35 bucks'. We've removed the caveat that you had to be a bit forgiving with it. Now it's just good."

http://www.engadget.com/2015/02/02/raspberry-pi-2/