To be honest, I don't think it's a completely indefensible 4th down call. He's down big and he took a gamble (especially after being stuffed on 3rd and inches). I might have gone for it there as well, or tried a fake punt like Doom suggested. The idea is to arrest some of the momentum, and considering DVO acknowledged that's exactly what it accomplished, it seems like it was a smart tactical move.
The standard for going for it on 4th has always been that you should be able to defend the decision in the thread. I really don't think this one was that terrible, though I'd like to hear what fero and uber think about it as well.
I suppose I could be persuaded to agree with that. I take more of the same stance WV does - I don't want to deal with this kind of thing so I don't do it.
The other side of that is would a NFL coach do it? To that I'm going to say probably not. Not that Romeo Crennel is a top coach but last week with 6 seconds left before half they had a chance at a 55 yard FG and punted it. To me that is a bit over-conservative but the point is the same, real coaches are conservative. If the Saints don't make that 4th down then they go down by 28 and the game is most certainly over. If he is so skilled his defense would have stopped the Falcons and he would've gotten the ball back.