Answer: everything. But to have known that, I guess you'd have to be able to identify the man starting at the 8-spot for New York's NL team. And no, it's not Carlos Beltran.
Multiple outlets are reporting that the Mets have announced a change to their starting defensive unit: the aforementioned Beltran will be shifted to right field, to allow Angel Pagan to start in center.
Yes, it's that Angel Pagan...
...the one-time fourth outfielder for the Cubs. The Cubs traded Pagan to the Mets -- his original team -- in January 2008 after a lackluster 2007 campaign, through which the young outfielder suffered through a bout with colitis (inflamed large intestine -- egads!). The Cubs moved Pagan in exchange for two young "prospects" who were widely regarded to have zero shot at contributing at the major league level, in an effort to free up a spot on the roster for Matt Murton (who is now the record holder for hits in a single season!... in Japan).
So what happened after Pagan was traded? Well, all of a sudden, he got good. Actually that's not true; Pagan's '08 campaign wasn't exactly stellar, although his .275/.346/.374 slash line and decent glove made him a league-average centerfielder, which is actually a reasonably valuable commodity in this league.
But in 2009, both his batting average and slugging percentage increased substantially. In 376 plate appearances over 88 games, Pagan posted a .306/.350/.487 line (a better OPS than every Cub starter not named Derrek or Aramis). And in 2010, when the Mets rewarded him with an increased workload, a lot of that average and power stuck, giving him an above-replacement value of 4.9 WAR according to Fangraphs.
Yes, hindsight is 20/20. But if the Cubs were just a tick better at evaluating talent, maybe there wouldn't have been a need for Kosuke Fukudome, or Milton Bradley (who begot Carlos Silva), or for Marlon Byrd (yes, he's fine, but he's not great, and he'll cost several million dollars more than Pagan would have over the course of his contract).
I know this is a tired and fruitless exercise but I figured I'd throw it out there. Feel free to ignore it now that you've read it all the way to the end...?