Suggestion to buy a game console

Hi
My friend wanna to buy a new game console
He interested in both ps3 and xbox 360
But he wants know in future which one goona to come soon after
Ps3 and xbox 360
I means Ps4 and Xbox 720
Because if it gonna release any one soon
he said waste of buying now
So please suggest which one can buy And as well as
which one goona to release soon either ps4 or xbox 720