There's just too much power up for grabs, too much money, and too many other addictive ways to keep score. And nobody watching the henhouse. I doubt the tea parties will stand uncorrupted - in fact, I don't believe they are now. It will take a lot more than what they're capable of to clean house. I wonder if it's even possible now.
I'm pretty deeply involved in the Tea Party (just as an observer, not organizing). There is no corruption, at least at the top levels (there still is no cadre of leaders, maybe that is why). It's a very novel group in that matter.
I'm not so sure, no movement that size with no real leadership is going to be without infiltrators. And let's face it, the movement grew out of the Libertarian movement - which is the real RNC threat at the moment. I'm kinda partial to the Libertarians myself, and don't like to see the way a lot of their groups and movements have been co-opted, but that's a different story.
I have nothing against the tea partiers, it's speech and I'm a big advocate of speech even when I disagree. But I doubt it's going to make much difference in teh long run, I also doubt the majority of the movement will stay independent. Call me cynical, but while speech can draw attention to certain issues if done wisely and well money and connections make the political world go round.