As David and Jonathan have mentioned, Barack Obama has announced that he will opt-out of the public financing system for the general election.
It seems obvious, as David noted in his article, that Obama's decision was made for political expediency and was not the principled stand his campaign is hoping people will see it as. The media has done a good job of covering the political side of this story. Obama is making a politically expedient decision and essentially going back on his "Yes" answer to a questionnaire that asked whether he would forgo private financing if his opponents did the same. But the other part of this story, the policy side, is sorely missing.
Obama may be making excuses when he says the public financing system is broken, but he's right. It seems inconceivable that the Supreme Court will allow limits on Swift Boat-type political speech anytime soon. 527s and their ilk are likely to remain legal, and to continue impacting elections. Money will still matter. To expect otherwise wouldn't just be naive, it'd also be missing half of the point.
The difficulty is not that there is money in politics or that people pay money to put political ads on television. The problem arises when politicians become dependent on money from certain lobbyists or bundlers or PACs or individuals. Obama has taken a big step towards rectifying that conflict of interest by refusing money from PACs and federal registered lobbyists. Just as important, he has asked major Democratic donors to avoid funding outside groups and give money exclusively through the campaign.
Taken together, the focus on small donors, the refusal of PAC and lobbyist money, and the attack on independent Democratic groups point to an entirely new way of funding a campaign. Obama has already been praised by the right for understanding and valuing free market solutions and for saying that government isn't always the answer to social and economic problems. In this case, the Obama campaign seems to have accepted that money is in politics to stay, and that attempts to remove its influence will inevitably be subverted by forces like the 527s. By opting out of the public financing system, Obama is acknowledging that money will always play a crucial role in American politics. But by discouraging donations to independent groups, focusing on small donors, and refusing PAC and lobbyist money, he's also trying to insure that money plays the right role in American politics.