Well, if there is no other way around this, I think it's better to apply Martin's patch. At least then we will be able to enter any valid utf-8 character in IDLE (although print statement won't print correctly unless the string is decoded first).

(As a Windows user, currently I can't print u'йцук' in interactive mode and get an "Unsupported characters in input" error because my default system encoding (cp1256) can't encode Russian.)

Also it will be more Unicode friendly which is not a bad thing.