The only think that gets me is Buckhalter will eventually flame out. I just cant see continued scoring production for the year.
Cutler is an upgrade over your current QBs. I assume you ride with Shaun Hill.
Your taking a downgrade at RB2 from Slaton to Buckhalter to move up to QB1 from QB2.
Looking ahead the next few weeks:
Cutler is about to run into a stretch of soft pass defenses. He closes in fantasy playoff time however with STL, Minny twice, Green Bay, and Baltimore. Not so good if you make the post season.
Slaton isnt too terrible from here on out, including playoffs. He will still need to face Indy twice, Jax once, along with San Francisco. Id expect a consistent 12 points a week out of him for the most part.
Buckhalter will kill you. Here is the schedule for Denver the next few weeks:
Dallas, New England, San Diego, Baltimore, Pittsburgh, Washington, San Diego, and New York Giants.
Overall IMO it is a matter of if you feel the upgrade at QB is worth the downgrade at RB. Seeing as how you are depending on Slaton as a usual starter and would have to replace him with Buckhalter, your basically throwing the baby out with the bath water in this deal.
If you get 4 points per passing TD Id stand pat or try to work something with a different back or trade suitor to improve your QB position. If you get 6 points per passing TD I might do this deal depending on how much interceptions cost you.