I don't think you will see either Microsoft or Sony launching a new console very soon. Both of these companies want to recoup their investments with this generation, so they will try and stretch this gen out for as long as they possibly can.
With this being said, I would imagine that if it is at all possible Microsoft would really like to get another year head start on Sony. But I think Microsoft has learned a valuable lesson this time, and they will not rush things as much (so they don't have a repeat of the RROD).
"If you've got them by the balls their hearts and minds will follow."
Quote by- The Imortal John Wayne, the original BADASS!