As far as I'm concerned, you don't trade Jennings for prospects. You get a guy or guys who can help you right now. I don't trust the Rockies scouting staff enough to choose prospects and even if any of them pan out, they'll eventually peddle them off because they don't want to pay them either.
Another Rockies rumor has them talking to the Angels about a deal that would send Todd Helton to Anaheim for Figgins, Kotchman & Aybar. Word is that this deal likely won't happen because the Rockies aren't willing to pick up as much of Helton's contract as the Angels want them to.