Kate Walsh Is Engaged.... Grey'S Anatomy star Kate Walsh is engaged to boyfriend Alex Young after a whirlwind romance.Young, the Co-President of Production at movie giants 20th Century Fox, proposed to the actress, 39, last week (ends11May07) in San Francisco, California, presenting her with a Neil Lane Jubilee-cut diamond ring.Walsh gushes, "He's the most amazing man I ever met."The news of her impending marriage comes shortly after U.S. TV network Abc announced Walsh is to star in her own spin-off of the hit medical drama, with her character Dr Addison Montgomery-Shepherd fronting Private Practice.The show is also set to star Lisa Kudrow, Taye Diggs and Tim Daly.