http://www.cnn.com/2000/SHOWBIZ/Movies/05/22/obit.gielgud.ap/index.html
These articles are from the NY Times, so you may have to register to see them:
John Gielgud, 96, Dies; Beacon of Classical Stage
Remembering the Still, Simple Beauty of Gielgud’s Art By BENEDICT NIGHTINGALE
The author of that last article speaks of Gielgud’s 1974 performance of Prospero in The Tempest: “…we in the audience had the spooky feeling that we were seeing Shakespeare himself using his last play to bid farewell to the stage.”
And "The great exponent of the Method, Lee Strasberg, who might have been expected to have been hostile, once said that ‘when Gielgud speaks the verse, I can hear Shakespeare thinking.’ "