funny i just noticed this tonight.
i typed something, and saw down below it was suggesting apps. I didnt think i ever noticed it before.
so because i noticed it, im guessing there is no setting.
cool feature though, long overdue
EDIT, just played a bit and it doesnt seem very consistent. Jesus how do they screw that up?? Google is a search giant!! Of all things they could screw up, the search method and suggestions shouldn't be one of them lol