It is an upper class setting, of course, but since all wizarding children in Britain and Ireland have to visit the school, I understand, there'd have to be working class children. But if Rowling doesn't give them the accents, we'll not so easily find them. Snape is one, one might argue, but one who managed to work his way up to upper middle class - we only find out about his background in book seven, really.

Anglesea (well, Anglesey, actually; I don't know if "Anglesea" is a misspelling in my book, a misspelling in the original, or a correct spelling of some obscure place not known by Wikipedia) is an island off the coast of Wales.

And yeah, good point. We do see it again once, I seem to recall... in book seven perhaps? I know Ron and Hermione are there, then, too.