I do not see much evidence that the tea party is cooling down.
But we are in the summer siesta season for politics in general. The primaries are by in large over, the General election campaign will not see much activity until after labor day, little money is being spent on television commercials because most of that is spent in October, and the bulk of the American electorate is more focused on anything but politics.
And to somewhat make a liar out of the OP, there is another tea party thread on P&N running at the same time as this thread.
I somewhat liken the tea party to mosquitoes, there will be another huge outbreak around October/2010.
Meanwhile enjoy their abstinence, they will be back and buzzing in your ears too soon. Driving all of us nuts and sucking all the sense and blood from our brains.