Edwards strategist Joe Trippi, my favorite theoretician in the Democratic Party, has an interesting blog post up arguing that Iowa in 2008 will not by a reprise of Iowa in 2004, when John Kerry coasted to victory after what Joe has called a murder-suicide involving Dick Gephardt and Howard Dean. The post comes in response to questions about whether, by aggressively taking on Hillary, Edwards will hurt both her and himself, allowing Obama to claim the top spot. Joe makes a couple good points, one of which is that Obama is also mixing it up with Hillary--only not as effectively--so he's hardly an innocent in all this. (On the other hand, it's not as though Kerry never took shots at Dean.) Joe also points out that Edwards's strategy is a pretty authentic expression of who Edwards is, and of his experience as a trial lawyer in particular--something I agree with and am actually writing about for our next issue.
The thing I'd add is that I'm not convinced it was blowback from his attacks on Dean that did Gephardt in in 2004. If I remember correctly, Dean attacked Gephardt pretty aggressively in response, something that seemed effective at the time. (One Dean ad showed Gephardt in the Rose Garden with George W. Bush and Trent Lott after signing the Iraq war resolution, which he'd co-sponsored in the House.) So unless Hillary starts landing some body blows against Edwards in the next two months, I don't think you can expect Edwards to suffer Gephardt's precise fate. (She may choose to go that route, of course, but there's no indication of that so far.)
That's not to say Edwards is going to surge to victory in Iowa. Just that his get-tough strategy isn't necessarily flawed in its conception.