Tonight's season finale of Grey's Anatomy will feature the final appearance by original cast member Sandra Oh, who plays Cristina Yang. Will people tune in to see the conclusion to what has arguably been the show's best and most enduring relationship, Cristina and Meredith's friendship? Last week's episode earned a 2.5 adults 18-49 rating, down from a 2.6 the previous week. The show's season high was a 3.4 adults 18-49 rating, for its two hour season premiere. How do you think the finale will rate? Make your prediction!