How's the NL Central shaping up for 2015?

We know where the Reds stand, but with (probably) the majority of the dominoes fallen, how does the rest of the NL Central look?

Chicago Cubs

In: Jon Lester, David Ross, Jason Motte, Jason Hammel, Miguel Montero, Tommy La Stella
Out: Justin Ruggiano, Carlos Villanueva, a bunch of prospects

Obviously, the big move here was the Cubs' signing of free agent starter Jon Lester. They also brought back Jason Hammel for their rotation, and look to have significantly upgraded their catching situation. Motte helps provide depth in the bullpen, but the biggest move the Cubs made was hiring Joe Maddon as manager. This is a team with a lot of youth that will have to produce for the Cubs to contend in this division, but they've been bringing in pitching and depth and probably aren't done.

St. Louis Cardinals

In: Mark Reynolds, Matt Belisle, Jason Heyward, Jordan Walden, Dean Anna
Out: Daniel Descalso, Shelby Miller, Justin Masterson, A.J. Pierzynski, Jason Motte, Mark Ellis, Pat Neshek

I'm going to go out on a limb and say that the Cardinals aren't done, but they've already gotten better. Jason Heyward adds another bat to a strong lineup, but they'll likely be relying on their surplus of young pitching to fill the holes left by free agency. I think they'll grab another arm, though.

Milwaukee Brewers

In: Adam Lind, Juan Centeno, Luis Jimenez
Out: Marco Estrada, Rickie Weeks, Francisco Rodriguez, Tom Gorzelanny, Zach Duke, Mark Reynolds, Lyle Overbay

Here's a team who have done less than the Reds have, so far! The Brew Crew may still have something up their sleeves, but for now, Adam Lind looks to be their only acquisition who will play everyday. They've done a couple of other scrap heap moves, but haven't really lost too much. They need a bullpen, probably.

Pittsburgh Pirates

In: Corey Hart, Radhames Liz, Sean Rodriguez, Antonio Bastardo, Pedro Florimon, Francisco Cervelli, Jake Elmore, Jung-Ho Kang?
Out: Gaby Sanchez, Ike Davis, Justin Wilson, Russell Martin, Edinson Volquez, Clint Barmes

The Buccos have been busy, especially now that it looks like they won the bidding for SS Jung-Ho Kang. That'll be an upgrade of Clint Barmes, and it looks like they'll move Pedro Alvarez over to 1B and install Josh Harrison as their everyday 3B. They didn't really have a ton to do, but they could still use another starting pitcher or two.

Looking around the rest of the division, how much better do the Reds need to get to challenge for the title?