If the Saints don't pickup another RB to split carries with Bush, Pierre could easily be worth as much as D. Williams. Don't forget the Williams will be splitting carries with a completely healthy J. Stuart this season.
Biggest question... can you start 3 RB? If not, I may change my answer.
It's actually a fair trade when you look at it.
ADP (just a regular league)
DWill 1.10 Pierre 4.06 Orton 10.04
So essentially you are dealing a 4th, a 10th and 2009 2nd rook and an 2010 1st
for a 1st round pick and 3rd round rook.
I would say if you feel you are going to be one of the top 3-4 teams in your league... why not make the deal. BUT.... I would still counter. This guy will give up more than that. Either get the 2009 2nd thrown out of the deal or get him to add a 2010 2nd for starters.
While I expect D-Will to keep his production up despite the return of Stuart, my internal Occam's Razor cries, "WARNING! WARNING!" This trade is not only a freakin' furball, it's also a bad deal for your future. I'd nix it, and attempt a simpler, less long-range set of negotiations.