What is solo life like for a level 60 Holy Priest?

Can a level 60 Holy Priest hold his own in a non-group setting? Do they fare well in 1v1 W-PvP? Can they farm gold well? Can they efficiently kill mobs?I plan on making a priest but the whole possibility of having to switch back and forth between shadow and holy dozens of times is turning me off. Is this not actually a big deal? Will I be able to handle every instance of the game in the same spec i'd raid in?