Walter Pincus knew Valerie since 1996
Woodward testifies in CIA leak case
Text: Bob Woodward's Public Statement
Pincus: Woodward 'Asked Me to Keep Him Out' of Plame Reporting
PS: I should mention that on that first link, I haven't been able to confirm the agent referred to in the article was Plame and other researchers I've talked to have argued that it wasn't, so take that FWIW, but I include it for reference on the topic of Pincus and Plamegate.
Thank you!