The position of the DLC and status quo is that we should look at the polls, take the popular positions, and we will win. When polling was a new tool, this was an effective strategy. As the Republicans have shown us, that is not enough any more. Leading is about more than just getting power and governing by polling. Part of leading, as the word implies, is persuasion. It's not just taking the popular positions and selling the candidate, it's also about "selling" positions, too. To do that, we will need to reform the Democratic party and invest in a liberal message infrastructure.
A message infrastructure will put the Democrats on par with Republicans, but it is not sufficient for them to overtake them. We need to do more than the Republicans if we want to do that. Deans' candidacy gave us a glimpse of what involving the grassroots/netroots has potential to do. I can't say what exact form that involvement should take, but it could be just what the Democrats need to give them the edge they need.
Without reform, however, the Democratic party will be consigned to permanent minority status, and risks facing the same fate as another major American party - the Whigs. So the question isn't if the Democratic Party will be reformed, it's a question of how soon and how painful the reform will be.