Allow me some hyperbole for a moment:
JJ Hardy is awesome. Marvelous. Splendid. Spectacular. He's aces. Boss. Brilliant
Really he's just a quality major league shortstop, but after Alex Cintron, Luis Hernandez, Brandon Fahey, Juan Castro, Freddie Bynum, Eider Torres, Julio Lugo, Robert Andino, and Cesar Izturis (who was probably easily the best player here), et al., you can see why he looks so good by comparison.
Hardy missed some time towards the beginning of the season, but he's certainly making up for lost time. Including today's game, he's hitting .299/.366/.514 on the season (162PA) with 7 home runs. He's going deep as frequently as any shortstop in baseball - his home run every 23.1 PA is second to only Troy Tulowitzi's 22.2. His wOBA - now at about .383 - trails only Jose Reyes'. Fielding numbers in small sample sizes don't mean much, but he's 9th in the majors (min. 200 innings) with an UZR/150 of +5.6. Not quite as flashy, but Hardy's also walking more often than in any season since his rookie year (9.3% BB), which places him in the top 10 amongst shortstops (min. 150 PA). He can field, he can hit, he's only 28 years old, and I'd like to have him in Baltimore until Manny Machado is ready.
All that said, Hardy isn't really quite this good. His BABIP is .327, even though his career mark is just .283. Sure he's hitting more line-drives than he has in years, but I'd still expect that to come down closer to .300 - which would make his line more like .278/.348/.486. The home run power isn't actually crazy - his home run per flyball rate of around 14% is more or less in line with what he did in Milwaukee in his first few seasons. The only difference is that he's hitting the ball in the air more than at any point in his career, which is resulting in more of them going over the fence. Slightly dampened flyball tendencies would probably have left Hardy with, say, 6 homers instead of 7. Then his line would be .271/.342/.458 - and if that's what he provides the team going forward, I have to think they'd take it in a heart-beat (even missing some playing time that's around a 4 win player). As high as I was on Hardy coming into the season, my "bounceback" line for him was only .275/.340/.440.
Dude can play, and right now it's neck-and-neck between Hardy and Wieters as to who's the team's MVP for the season. Guys that can get it done on both sides of the ball = win.
Stats: wOBA, BB% & K%, FB%, HR/FB%, BABIP, UZR, WAR