Like Variety's Anne Thompson, I'm not as familiar with Yang's work as I'd like to be; there are times when it seems that no matter how many fests I attend, how many foreign films and docs and indie dramas I see, I can never catch up and see them all, and it takes a death to make me realize that I've not seen or appreciated enough of this person's life work. I see a lot of Asian cinema, and still I'm almost completely unfamiliar with Yang's films -- something I intend to correct at the first opportunity.
Senses of Cinema has a solid write-up by Saul Austerlitz on the director and his body of work in their Great Directors section. Two of Yang's better known works are Yi Yi (his last completed feature -- Yang was diagnosed with colon cancer shortly after winning the award Best Director at Cannes in 2000 for the film), and A Brighter Summer Day.
Austerlitz writes about Yang, "His films express the confusion, anxiety, and sheer beauty of societal transformation. Yang also equates the macrocosmic and microcosmic, making the lives of his characters stand in for the greater, less visible processes of social change. Along with Hou Hsiao-hsien and Tsai Ming-liang, Yang is one of the most visible faces of the Taiwanese New Wave, possibly the most brilliant filmmaking movement in the world today."
Here's a roundup of some other write-ups on Yang and his work; as a whole, they give a nice perspective on the man and his films:
Mahola Dargis, New York Times: "Mr. Yang directed seven features that in their visual style and preoccupations - including the impact of modernization on the Taiwanese middle class - argue for his status as an auteur."
Green Cine Daily: "His movies focused on Taiwan, but they were not primarily about Taiwan. They were about humankind."
The Guardian -- 2001 interview by Duncan Campbell: "Like the small boy with the camera in A One and a Two, Yang seems now to be in the perfect position to use film to show people the parts of their lives that they normally miss."
Godfrey Cheshire, The Village Voice: " ... one of modern cinema's most fascinating careers passed largely unseen by American cinephiles."
Ray Pride for Movie City Indie: "I don't like to use the word "humanist," but that is one of the lesser things you could say of Edward Yang's Yi-Yi ..."