Setting aside the "flashlight as cool toy" part, until recently I thought of headlight vs flashlight in the same way that Jeff Cooper talked about handgun vs rifle... "a handgun is for fighting your way back to the rifle you shouldn't have put down in the first place".
Any time I had to operate in the dark for any extended period of time - whether it be walking, camping or working - I found a headlight to be much more useful, partly because it left both hands free and partly because the light automatically pointed where I was looking.
I still used flashlights more, simply because I haven't had time to do much outdoor recreation at night, so when I need a light it's usually because something unplanned happened and that's where flashlights are so valuable.
The only thing that has changed recently is that I have picked up a flashlight with a decent combination of magnets and light patterns (a Streamlight Duallie 3AA) which has been sufficiently useful that the headlight hasn't seen so much use recently, to the point where I have gone back to storing it with the batteries removed in order to avoid leaks. Yes I need to replace the alkalines with NiMH AA's.