I think it's more likely that England would remain Catholic, though we would still see some sort of Protestant movement flair up in the country. While the monarchy might have reason to struggle with the Church (particularly if Arthur's headstrong little brother becomes a clergyman) without a converted monarch Protestantism would not get a much needed boost to really establish itself on a societal level, and the counter-reformation would at least solidify Catholicism's hold on the majority if it doesn't stamp out the Protestant movement.
EDIT: I may be slipping to "great man" theory of history here, but I really do think that Henry's unique situation of no sons and stubborn personality was instrumental to a successful break with the Church and his and his successor's willingness to compromise with established Catholic religious practice while bringing in the new faith was vital to making Protestantism palatable enough for the majority of English to adopt. A monarchy which did not want to break with Rome and a Protestantism lead by grassroots reformers who wanted to radically change religious practice would make the creation of a Protestant England a lot harder.