There have been WAY to many lately - just look at the list of guys (some who Omar traded, many here crucified Omar for it... but guess what, even if the aging player we got in return didn't perform all that well we didn't really lose ANYTHING:
Lastings Milledge - traded for Ryan Church who actually played great for us but concussions ended his career, shame too, he was a good player. And Brian Schnieder, eh.
Yusmiero Petit - Traded (along with Mike Jacobs) for Carlos Delgado, well Petit is now 27 and STILL hasn't made it to the majors for more than a cup of coffee, Jacobs... is he even in baseball anymore? And Delgado, well that goes without saying, we won.
Scott Kazmir - 28 years old and now out of baseball, never was the super ace we thought he'd be, and while we lost, in the real long run we really didn't
Carlos Gomez, AND Phil Humber - well both aren't very good and we got Johan for them, and while Johan appears to be falling apart well before we expected him too, he did give us a couple good years and our first no hitter. We won.
Lets not forget the much older "highly touted" prospects we had that s--ked! Alex Escobar, Bill Pulsipher, Aaron Hielman.
Now name the ones who came up and became good/great players -
Uh... David Wright.
Murph... remains to be seen, not a star, but a good player. Tejada, again not a star, but a nice piece for a lot of teams.
All that said, aside from Wheeler I'd be willing to trade ANY of our prospects... for the right players in return. It'd have to be for talent already at the major league level that can come help us now. You don't trade prospects for prospects. I wouldn't trade one of our top prospects for a reliever either... because:
1. Relievers are IMPOSSIBLE to predict - one season they are lights out and the next they're AWFUL (see Ramon Ramirez)
2. Relievers don't sign long term deals. Only top notch closers do. Middle relievers no team signs to long term deals because of reason # 1. Often times your bullpen almost completely turns over every 2-3 seasons. I wouldn't trade a top position playing prospect for a guy who might help us for 1 or 2 years then sign elsewhere.