Unless we invent seriously good wireless charging, I just can't see that happening. There's too many cases where having your phone "docked" just doesn't work.
Personally, I usually fall asleep with my phone laying on the bed next to me playing YouTube/Netflix/etc. No way to do that if it has to be resting on a pad like the Watch.
And what about cars and navigation? Can't throw your phone in your cup holder and pull up Maps anymore. You either need a new car with wireless charging or need to strap some sort of wireless charging pad to the back, which defeats the entire purpose of wireless charging.