The election of Barack Obama in the US is a significant change, but it is a much smaller change than many people want to believe.
By that, I mean that the gulf between rhetoric and reality is bound to be painfully large, looking at the structures and assumptions within which his undoubted goodwill will have to operate. So the real issue is how we, "ordinary people", can use the tiny but vital bit of space opened up for justice and peace. It's no good expecting Obama to be a singular hero. I think he has humane instincts, but he is (of course) deeply wrapped up in the system he would like to redirect. I don't expect him to save us, and I shall not hate him when he doesn't.
If there is salvation to be had (and I fully respect those who doubt it, though I think any lesser hope is likely to be inadequate to the real challenges we face) it is going to be, in the words of the Hebrew prophet, "not by might, not by power, but by my Spirit, says the Holy One": that is, a massive refiguration of everything that is at stake, politically, economically, spiritually, interpersonally - starting not with overarching theory or messianic politics/religion, but with specific interventions and the cultivation of alternative ways of being.
This is what church as ekklesia and as part of the civic arena should be about. Not pipe dreams, but lived possibilities and concrete actions. There is a larger hope, but it starts in small places; it engages rather than overwhelms; and it is birthed by absorbing, sharing and transforming pain, not inflicting it by force of arms. It is Christlike. And it is rooted in metanoia, turning around and heading in a new direction.
All that said, it would be as dangerous to underestimate what Obama may open up for us as it would be to believe that a new dawn will be birthed in the White House, rather than some grubby stable.