I can see that there are mixed feelings about whether the BBC should end the series whilst it is all going well or to extend its life... However, I am strongly of the opinion that there is still much more mileage!! Anyhow, I recently created a small petition and encourage those who are like minded to sign up
Great forum btw
Link to more of ramblings around this topic on my blog (probably too much detail for the forum lol).
Petition link here ->http://www.ilovemerlin.com/blog/2012/11/29/bbc-canning-camelot-merlin-needs-you/