Castlevania: Order of Ecclesia for the Nintendo DS isn't quite the breakout title that rebirthes the series and takes it out of rehash territory. But even the most forgiving Castlevania fan can probably admit that, yes, the formula just might be growing a little bit stale. Like the NES Mega Man names, none of them are actually 'bad', but rather just varying degrees of 'fairly good'. Since the release of the PSOne title, there have been six more entries, all for portably Nintendo systems, within the past dozens years or so.
The release of Castlevania: Symphony of the Night in 1997 began a new subseries within the franchise, which we all know as 'Metroidvanias'.