I can say from living in San Francisco, which was a hot bed of Obama support, a lot of people are disappointed in Obama's performance. At the end of the day you basically have four options in 2012. You can vote for Obama again, you can vote for the Republican candidate, you can vote third party or you can stay home. A lot of Democrats are like Republicans where they may be pissed off at their own candidate but it doesn't mean they are going to vote for the other party.
This is not new to post an article stating Democrats are unhappy within varying degrees with Obama. Things change though quickly in politics. In six months he could be very popular again. Never underestimate the Republicans ability to shoot themselves in the foot. So I wouldn't write Obama's political epitah just yet.