Many of the reactions are predictable. I've tried to collect a few that seemed to have more insight than most. A couple are from before the speech.
Fred Kaplan - Confessions of an Uncertain Columnist
Lawrence Wilkerson - Damned If You Do, and Damned If You Don't
Robert Dreyfuss - Exit: 2011?
Stephen Walt - Instant Analysis of Obama's Speech
Steve Coll - The Speech
And Marc Lynch's piece, which Helmut linked below.
Plus this: President Obama to Leader of [Insert Country]: "Your Move" It's more general than the others, but makes a point that I made some time ago: Obama is a smart player. It's time for these other countries to do some of the heavy lifting. The United States does not rule the world. And that's a good thing.