I don't mind someone having a go at an accent so long as they don't balls it up. Some have failed spectacularly: Dick van Dyke's cockney in Mary Poppins and Robin William's 'English' Mrs. Doubtfire spring to mind.

Two things: Most importantly, Mrs. Doubtfire isn't really English; she's the hero's conception of an Englishwoman. So if the accent is mucked up, it's the character's fault, not Robin Williams's.

Secondly, I thought (from my American viewpoint) (s)he sounded more Scottish than English.

Dave Oesterreich