Since Miller is known for her WMD stories, I believe she sent Cooper down a bogus trail on the Cheney/Wilson story and then he, although possibly inadvertently, set Rove up. Otherwise, why would she be involved at all, considering she did not write a story about the Plame leak. Remember, Cooper originally called about a story he was doing on welfare reform, not the Cheney/Wilson controversy. That in itself is suspicious.
If you were Miller, and lost some credibility from your liberal friends, family, coworkers, readers and everyone else you come in contact with on a daily basis for the early WMD stories, what would be a great way to get back in favor?
Ooh, how about going to jail and becoming some kind of liberal beacon for no reason (since her apparant source signed a waiver)? She'll be more famous for what's written about her by her forgiving friends than for what she could write herself.