Here's a good analysis from Glenn Greenwald touching on why Obama doesn't have to appease progressives and a strong indication of why he will be a two term president:
http://www.salon.com/news/opinion/glenn_greenwald/" onclick="window.open(this.href);return false;In December, President Obama signed legislation to extend hundreds of billions of dollars in Bush tax cuts, benefiting the wealthiest Americans. Last week, Obama agreed to billions of dollars in cuts that will impose the greatest burden on the poorest Americans. And now, virtually everyone in Washington believes, the President is about to embark on a path that will ultimately lead to some type of reductions in Social Security, Medicare and/or Medicaid benefits under the banner of "reform." Tax cuts for the rich -- budget cuts for the poor -- "reform" of the Democratic Party's signature safety net programs -- a continuation of Bush/Cheney Terrorism policies and a new Middle East war launched without Congressional approval. That's quite a legacy combination for a Democratic President.
Whether in economic policy, national security, civil liberties, or the permanent consortium of corporate power that runs Washington, Obama, above all else, is content to be (one could even say eager to be) guardian of the status quo. And the forces of the status quo want tax cuts for the rich, serious cuts in government spending that don't benefit them (social programs and progressive regulatory schemes), and entitlement "reform" -- so that's what Obama will do. He won't advocate, and will actually oppose, steps as extreme as the ones Paul Ryan is proposing: that's how he will retain his "centrist" political identity and keep the fear levels high among his voting base. He'll pay lip service to some Democratic economic dogma and defend some financially inconsequential culture war positions: that's how he will signal to the base that he's still on their side. But the direction will be the same as the GOP desires and, most importantly, how the most powerful economic factions demand: not because he can't figure out how to change that dynamic, but because that's what benefits him and thus what he wants.
Obama is the consummate Chicago pol who will promise the greater number anything they ask until election day 2012. It's after that date that his true sociocommiepinkoislamoprogressivefascist (raised you one epithet, there, kalm!) colors will shine forth. 
