Yes. Definitely yes, if they haven't already! Not saying that because I think it is a good thing, it's just the way it is.
Until the beginning of the year I would never of used a phone to cache with. I am still hesitant now. I have a deep down feeling my ancient Garmin is still superior in some way than the using C:geo on my "apparently" smart phone. I have not gone out caching without my old GPSr, that was until Sunday just gone, where I fired up the app on my phone whilst I was in Avesbury for eldest son's football match, saw a nearby cache on it, headed straight for it, and found it almost straight away.
If many GPSr's had the functionality that phones do to be able to search for caches online and download the coords anywhere, anytime, then I may well of voted differently. I am not totally converted yet, but phones do have some benefits over standard GPSrs.