The parts of President Obama's speech that I heard last night (I was working and helping deal with kids) sounded much like President Bush's surge speech. I'd considered copying and pasting my post on his surge here, but instead decided I'd just echo my thoughts then - I referred to it as "hopeful pessimism."
I do hope the surge works to create some stability in Afghanistan, and I hope that it will give us the space to be able to withdraw safely and with some dignity - a la Nixon. But I'm unconvinced because we're dealing with a country that does not appreciate foreign influence and who has no stable centralized government.
I believe the invasion of Afghanistan was justified - more so than the invasion of Iraq (which the President had the authority to do based on the 1991 AUMF and subsequent cease-fire), and I think it's important to do our best to create some stability out of the mess we've helped make through several years of neglect and half-hearted commitment. For that, I am hopeful.
We'll see how it goes.