When Sony revealed the PlayStation 4 in February they announced that the new console would be available in late 2013, but weren't specific on which regions would see the new console then. According to GameStop executive vice president Mike Hogan, the 2013 launch window will in fact be global.
"We know that Sony will introduce the PlayStation 4 globally in 2013, but we are still waiting to see what Microsoft's final plans are," Hogan said during a recent earnings call (via Gamespot). "We have scenarios with one console introduction, as well as with two."
Microsoft is also expected to release the Xbox 360's successor for the 2013 holiday season, though the company has not confirmed this. Many expect Microsoft will hold their own media event sometime this month, similar to Sony's PlayStation 4 reveal.