User blog comment:Ḡwẵine Ḹٍٍkƨ Ĺiĸe Ͼềлȑềd/Series 5 will be the last! - unless we act now!/@comment-5209013-20120912091517

I just read the following on Tumblr, the tweet is from someone who's in Pierrefonds right now (I don't have a twitter-account, so it isn't the official link) : Anna Lyse ‏@cranberrymerlin ’ One guy of the Merlin-crew (I think a producer) said, that there has been absolutely NO decision about whether Merlin goes on or not. ‘

I reckon it's safe to assume that they've written the final episodes already, so if the above is true, it would mean that S5 will probably have an open ending. Either way, it would mean that the fifth season isn't going to end in the Battle of Camlann.