In a word, no.

But that's the claim Howard Wolfson peddled to the Times of London:

We would have won Iowa, and Clinton today would therefore have been the nominee. Our voters and Edwards's voters were the same people. They were older, pro-union. Not all, but maybe two-thirds of them, would have been for us and we would have barely beaten Obama.

In the same article James Carville is a bit more circumspect:

My instinct tells me that she probably would have done better had Senator Edwards not been on the ballot in Iowa, but that wasn't the circumstances at the time.

The circumstances at the time were that Obama and Edwards were fighting for the same anti-Clinton vote, which constituted the more liberal part of the Democratic base. In fact, Iowa entrance polls showed Obama beating Clinton 2-to-1 as the second choice of Edwards voters. With the evidence we have the best conclusion is that without Edwards in the race Obama would have done better than his 10-point margin over Clinton.

Clinton's problem in Iowa wasn't John Edwards. It was Clinton, who got steamrolled by her two better organized opponents. That certain staffers can't come to grips with this eight months later is a telling aspect of the entire campaign.