GREY'S ANATOMY - "I Am a Tree" - Cristina meets Burke's parents -- and in the most awkward of circumstances -- the interns campaign for Izzie's reinstatement to the surgical intern program, Addison takes a break from her hospital duties, and a surgical patient lives what may be her last day to the fullest, on "Grey's Anatomy," THURSDAY, SEPTEMBER 28 (9:00-10:01 p.m., ET) on the ABC Television Network. (ABC/VIVIAN ZINK) SANDRA OH, RICHARD ROUNDTREE