Speaking for myself, no, my smartphone does not replace my tablet. The amount of screen realestate lost when going from 11" to 5" is just too much. It makes reading hard (particularly with less than perfect eyesight), movies too small, and all of the real time communication that comes with a phone is vying for my attention all the time.

Now then, if I could make calls over a bluetooth headset connected to my iPad, I'd drop my phone in a heartbeat...