His power stroke has never been in question. His plate discipline has been. But Vlad Guerrero in his heyday was pretty good without plate discipline, too.
Sure it's a hot streak, and a slugger like Viciedo will have his slumps, but when it's all said and done he should finish the season with 30 homers, 80-90 RBI and, well, a .250 batting average at best.
I've been watching his at-bats for the past three weeks and he has excellent plate coverage. He hits breaking pitches just as well as he does fastballs. He's developing into a true threat before our eyes.
If he ever walks even a third as much as he strikes out, he's going to be an absolute menace.