My commutes this week have been depressing and no fun at all due to chain slippage. My bike has only 950 miles or so on it, so I'm surprised if it turns out that the slippage is because of wear on the drivetrain. I tried fine tuning the derailer hoping that might be the problem, but no luck. So it's off to the LBS tonight to see what they say about it.
I'm seriously bumming about this. My commute is often the best part of my day and it sucks beyond all belief to not be able to accelerate effectively.