Phil is committed to the Premier League but after that who knows? Sky would offer him a job in the commentary box - either Harrington or Mardle would have to move on.
There's so much else he could do too - PDC ambassador to develop the sport around the world, bridge-builder with the BDO, developing the sport from grass roots. Definitely time to retire in the summer, mainly because there are so many opportunities in the sport away from the oche.
Whatever he does, and whenever he does it, he'll always be a complete legend. Very much doubt to see any sport dominated to such a degree, over such a long time, in my lifetime again. Nice bloke too by all accounts.