It is true that they made a lot of mistakes (some detailed here:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=132x5883262), but Obama's campaign has done some amazing things and I don't think that the Clinton campaign could have been expected to predict its success (that doesn't mean that Penn wasn't a huge waste of money, of course).
I've been involved in politics a while and I understand the narrow targeting, big-state, 50+1 strategy that has characterized politics for years. I understand why the Clinton campaign would focus on likely voters (historically, new voters and young voters don't vote). In any other election against any other candidate, it probably would have worked.
I was an Edwards supporter to begin with, but Obama won me over. Not necessarily because
I find him inspiring, although I do at times. But because I find his campaign amazing.
It's amazing on two fronts. The first is that his campaign does transcend politics. Not because of any particular policy issue. Policy-wise and in voting records, he and Clinton are very similar. His campaign transcends politics because it isn't the narrow targeting strategy. He has been able to get new voters and young voters to actually turn out. Howard Dean tried in 2004, but he couldn't make it work. Obama has been able to make it work.
Secondly, the Obama campaign has had a remarkable ability to predict voting outcomes, which is all the more remarkable because of high turnout. There is a reason that Tim Russert keeps pulling out that delegate total spreadsheet that got "leaked" in February. There is a reason the talking heads kept marveling at how close the Obama campaign's updated Indiana prediction was. It's because people who have covered politics for a long, long time are surprised at how good they are.
I also understand why Clinton supporters, especially experienced political hands, are so frustrated and don't "get it". On paper, there is no reason why Obama should have been as successful as he has been. A unique confluence of events and a remarkable campaign have pushed him over the top.
I don't think that it will be easy to beat McCain (it wouldn't have been easy for Clinton, either). McCain's a lousy candidate, but the electorate is highly polarized, because of the narrow targeting political strategies both parties have used for years. But Obama and Obama's campaign have been surprising so far. I'm excited about where it will go from here.