The Met has the services of several countertenors -- the Julius Caesar revival 5 years ago had three, plus a female mezzo en travestri. It certainly hasn't been leaving A Midsummer Night's Dream alone for lack of Oberons. When the opera was on the company's schedule for 13 performances in 1997 and 2002, five countertenors did the role at various performances: Jochen Kowalski (he got the most), Derek Lee Ragin, Leon Varkas, and Mr. Daniels.

I adore the opera myself, but I'll be surprised if it comes back any time soon.