I think Obama has reached the point of diminishing returns with his speeches. Big numbers of people are tuning him out, and don’t really care what he has to say.
If he was expecting to have a bunch of Presidential campaign speeches in 2012 broadcast for free, either from the Oval Office or from Congress, he may need to rethink that in terms of how effective it would be, and figure on using his billion-dollar campaign kitty for his campaign ads (probably 95% attacking his Republican opponent and 5% taking credit for killing Osama bin Laden).