The last couple of days have brought some interesting news on the centerfield front, with NL East rivals Atlanta and Washington both making significant upgrades to their rosters. The Braves inked BJ Upton to a 5 year/$75 million dollar deal yesterday as the continue their ongoing quest to add some pop to their lineup. Today the Nationals responded by swapping pitching prospect Alex Meyer for former Twins’ centerfielder Denard Span. These two franchises each won over 90 games a year ago, and their aggressive attitude (or Nattitude) early in free agency should pay dividends in 2013. Let’s take a look at the move each franchise made, as well as what it means for the rest of the National League East.