How does Oliver Parker's 2002 film The Importance of Being Earnest compare to Oscar Wilde's play?

Oliver Parker's 2002 film adaptation of Oscar Wilde's play remains relatively true to its source material and does not compromise Wilde's satiric playfulness.  The play points out and pokes fun at many of the flaws of the Victorian upper class -- especially their tendency to adopt a very high moral tone while, simultaneously, indulging their less acceptable, but very human, desires -- and the movie retains this purpose.  In the interest of pacing, the movie does mix elements of the first and second acts of the play; therefore, the audience meets Cecily, Ms. Prism, and Doctor Chasuble just after becoming acquainted with Jack, Algernon, Gwendolyn, and Aunt Augusta.  Rupert Everett is a perfect Algy: irreverent, charming, and lovably and incurably dishonest; likewise, Reese Witherspoon's Cecily, fantasizing that she is the heroine of some pre-Raphaelite painting, is appropriately hilarious and absurd.  The movie is as smart and witty as the play, its satire as playfully pointed, and the casting is superb. 
One major difference, however, is that the play ends with Jack finding that his name really is Ernest, but the movie ends with him learning that his name is actually John (for which "Jack" is typically short).  Perhaps the movie's producers felt that the play's ending was a little too convenient; further, making the choice to have Jack end the film with a lie (when he tells Gwendolyn that his name is really Ernest) makes it clear that he will not change, and that he will continue to be trivial until the last.