The date of separation is listed as November 22, 2008, just before the Thanksgiving holiday. According to the filing papers, Alex cited irreconcilable differences.
Kate and Alex married in September of 2007.
Something crazy must have happened between November 9 and 29 as the couple looked quite happy together in Las Vegas!
UPDATE: Kate‘s reps tells JustJared.com, “Papers have been filed to amicably end the marriage of executive Alex Young, and actress Kate Walsh. The couple remain on friendly terms and sincerely hope the media will respect their privacy during this difficult time.”