As much as I like what Arroyo's done here, I think he's the guy you have to trade if you want to make a run this season. Trading prospects for FA's-to-be would be unwise, as this is still a flawed team with most of its core players several years from their respective primes. It's not worth wasting Jay Bruce's best years because you went all-in on a 2009 team whose best possible outcome is a one-and-done in the playoffs.
But, the division is there for the taking. You never know how often these kind of chances will come around, so you have to do something, right?
If this team is to go to the playoffs without mortgaging the future, the most probable scenario (really, the only scenario in my mind) is to add a bat, get Volquez back healthy, and have some combination of Bailey/Maloney/Ramirez cobble together enough quality innings to maintain the strong pitching we've enjoyed thus far. That last part is a lot easier to do when all you need to do is equal the 5.16ERA Bronson's given you to this point. You can't ask rookies to replace Harang's production.
So, where to send him? I look at Minnesota; a .500 squad in a division that's eminently winnable, with a 109 OPS+ and a 93 ERA+ as a team. They have 4 outfielders with at least 170 PA's, plus a DH who's a nominal LF. One of those OF's happens to have a career 109 OPS+ (Bronson has a career 106 ERA+), happens to have a contract that pays him $16.5mil over the next 2 seasons with an $11mil option for 2011 (compared to Bronson's $22mil over the next 2, plus an $11mil 2011 option), and happens to bat righthanded.
CF Stubbs R
1B Votto L
LF Cuddyer R
RF Bruce L
2B Phillips R
3B Encarnacion R
SS Shit, what's that one guy's name?