Here's my guess as to what is going on:
1) Dean wants to clean house at the DNC, as you have already noted yourself. He owes the Clintons NOTHING; he was already governor of Vermont before Bill Clinton became president, and was still governor when Bill Clinton left office. He probably considers them as sleazy and damaging to the Democratic Party as we do, albeit for slightly different reasons. (I think he probably views them as the Greens and Naderites do: As "traitors to the cause.") He'd love to remove as much of their influence as possible, regardless of whether or not he wins the nomination.
2) Dean is currently the perceived frontrunner for the nomination. (I still personally believe he's more vulnerable than everyone else thinks, but for the purposes of this post, I'll go along and presume he's in front.)
3) Hillary believes that none of the other RAT candidates have a chance in hell of winning against Bush under any circumstances, except for Dean. Worse, Dean openly wants to de-Clintonize the Democratic Party, while none of the others do. (And Dean can accomplish a LOT of de-Clintonization merely by sewing up the nomination. He does not have to wait for a win in November 2004 to do this.) So Dean's not just the only threat to her 2008 chances; he's also a threat to her remaining control over the Party. Thus, Dean must be stopped.
4) Hillary knows that Wesley Clark has an ego the size of Jupiter and is just itching to jump into the race. She also knows he's got so much baggage that he's got about as much chance of actually winning as Dennis Kucinich does. However, he does have one all-important quality that the other candidates lack: He appeals to many of the same crowd that are currently salivating over Howard Dean. So she orders her closest confidantes, the true kneepadder crowd, to go work for Clark, telling them she thinks he's the RATS' best chance in 2004. Being lapdogs, they dutifully follow orders.
5) At the same time, she makes a deal with Clark: "Look, you know you're not going to beat Bush, and neither am I. But if you go out there and get enough support to stop Dean, ensuring that somebody else wins the nomination, then I'll make you my VP candidate in 2008." Weasely Clark accepts in a heartbeat.
So that's my theory in a nutshell: Hillary fears nobody except Howard Dean, and Dean's increasingly looking like he just might get the nomination. So she seduces the power- and attention-hungry Clark into playing the role of her stalking horse in 2004, with only one objective: Stop Howard Dean.
Come 2008, of course, she won't even return Wesley's phone calls, unless her pollsters tell her he'd actually be her ideal running mate (which is extremely doubtful). She's just using Clark, and for all his supposed brains, he's dumb enough to fall for it.
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
Gee - Thanks for the imagery there, Timesink!!! ;-P