Vick is so elusive that the "spy" approach probably would not be effective against him. I don't know if other teams have used it against him and whether it's worked for them. My guess would be no.
I think all of the pass rushers will have to be very disciplined. If only three are rushing, then a spy might be helpful, but it's probably best to rush four or more on every play and maintain gap discipline and contain the edges. It will be interesting to see if Woodson can do what Winfield did against Vick last week.
Getting back to Cullen Jenkins: He would be a huge help against Vick, obviously. I think he will play.