Remember Jimmy Johnson favors a different kind of offense and defensive scheme. We've got the players who best suit a 3-4 defense and doubt Johnson interested in coming back and doubt Jerry Jones wants to waste time rebuilding again while we move back to schemes Johnson would want.
The next coach of the Cowboys after Parcells calls it quits (and I believe Parcells will be here thru 2007) will be someone from the Parcells-Belicheck family tree who would play the same offense and defensive schemes.
Don't believe it will be Zimmer either. Cowboys made no effort to stop him from meeting with Rams re their head coaching job. If they believed Zimmer was their man, they would have asked him not to follow thru on that meeting, etc. I think Parcells likes Zimmer but doesn't always like his schemes. The addition of Hatcher, another DE who has potential to get to the QB, reinforces my belief that Parcells intends to ensure we get pressure on the QB, including various blitzing schemes.