Taken at face value if someone had asked me if I thought Datsyuk would head back to Russia after his contract expires, at the age he'll be then (and the state of the team at the time), I'd strongly lean toward yes. Ultimately the state of the team is going to weigh heavily on that decision: if the team makes move(s) necessary to keep the team as a legitimate Stanley Cup contender the "loyalty" card to do something like Lidstrom's play-it-by-year contract re-signings seems to be a strong possibility.
But the status quo of the last couple of seasons? Happy trails, Pavel, and enjoy the company of your daughter. Couldn't ask for more from him.