This article is amazing, the author is berating the Obamanites for their high expectations and is urging them to give Obama a break, he’s not their messiah:

The convention is practically over, but Barack Obama has yet to utterly transform U.S. politics or perform any miracles. Wheelchair-bound conventioneers are still in their wheelchairs, and the only loaves and fishes are those provided by caterers. The economy’s still in the toilet. The war in Iraq is still going on. Beltway insider Joe Biden is the VP pick, and Obama hasn’t even apologized for his vote on the Foreign Intelligence Surveillance Act. So where’s the change?
Poor Obama. When Hillary, Michelle, Teddy and Bill act like normal people, everyone’s happy. But Obama’s never allowed to just be a regular guy. He’s supposed to be a cross between a new Jack Kennedy and a new Martin Luther King Jr. — someone who can transform politics-as-usual, cast aside the old divisions of race, class and partisanship and lead us into a future full of hope and … you know, change. He’s supposed to be transcendent.
[…]
Democrats should give Obama a break. He’s not the messiah — as his wife has dryly pointed out, he’s an ordinary mortal, someone who doesn’t always pick up his socks off the floor.
Actually, he’s not quite “ordinary.” Obama is not the average American — who’d want an “average” president? His multiracial background is striking, and he’s smart, progressive, imaginative and charismatic. He can give a speech that makes you cry. But he’s also a regular politician. He takes full advantage of lucky breaks and knows how to compromise, bargain and play hardball. Occasionally, he makes dumb mistakes.

But he’s the one that has raised their expectations. He’s the one who has told them that he is a different kind of politician, that it isn’t going to be politics as usual.
And why shouldn’t they think of him as special since he’s been hyped that way.
So, their expectation is high, who can blame them for being disappointed to see that his campaign is no different from any other campaign (except maybe for the “Barackopolis“), that his running mate is a Washington insider who has been there most of his adult life. They expected change and they see that they’re going to get more of the same.