I was disappointed as well when Obama began to act like more of a centrist, but then I realized he was just being human.
Sometimes, it's really disappointing to find out that someone you've looked up to for a long time is, in fact, a human being, with all the faults and shortcomings that humans have.
For years, I followed a certain comedian as though he were some sort of sage. I hung on his every word, followed his advice, and paid close attention to everything he said. But one day, he said a few things and did a few things in one of his acts that deeply offended and insulted me. I was upset at first, but then I realized something. This comedian wasn't a god or a sage or some all-knowing power. He was just a man, with a talent, and though he was talented he would invariably make mistakes. He would also hold opinions I disagreed with or even found offensive. Why? Because he was some sort of crazy right-wing extremist nutjob? No, because he wasn't me, and just ebcause we agreed on some things didn't mean we'd agree on everything.
I think the same thing is happening now with Obama and many of his supporters, especially those who read the Daily Kos. A lot of people are indignant that Obama happens to not always agree with them. They're upset that he may not, in fact, end the war immediately, or that he's opposed to violent videogames, or that he's unsure where he stands on a number of other issues. But just because he's "your" candidate doesn't mean he's obligated to pander to your every interest. He's a human being, and he has his own thoughts, opinions and beliefs, and if you're willing to support the guy on a deep, honest level then you must come to accept that he will not agree with you in every way on every thing.
It's a shortcoming of our system that we have a president who is expected to represent everyone in the nation, which is of course impossible. And while it would be nice to have more than two candidates to choose from every year, we do need to understand that this is the system we've stuck ourselves with, and we can either change it or work with it. Right now what we should do is support, stick with and ultimately vote for the "best" candidate, regardless of how much we agree with him or can relate to him, and at current that candidate is Obama.
So don't let the fact that you don't agree with everything he says hold back your support. If you feel you're voting for Obama because you "like" him, then you're no better than the people who voted for Bush once or twice because they thought he would make a good drinkin' buddy. You should vote for Obama, and give him what donations and volunteer efforts you choose, not because you feel that you'd enjoy his presence, but because you think he'd do a good job leading this nation through what will be the biggest domestic cleanup since Nixon climbed into that helicopter.
Just remember that Obama is all too human, and as such, he's going to behave like one.