At his current pace he'll hit 730 before his 35th birthday.
This is all hypothetical, but let's say he averages 47 goals per season for the next 4 seasons. That puts him at 713, or about 181 short at age 35. I think it's still possible for him to make a run at it, as long as he stays healthy, there are no further lockout(s), or doesn't decide to go play in the K.
Providing he is able to average what I had mentioned, he would need to do the following to break Gretzky's 894 after he turns 35:
90.5 goals per season for the next two seasons
60.3 goals per season for the next three seasons
45.25 goals per season for the next four seasons
36.5 goals per season for the next five seasons
30.3 goals per season for the next six seasons
25.2 goals per season for the next seven seasons
I don't think it's as far out of reach as some can think. I can see him making a serious run at it when he's 40-41.