Just as a little aside with the Freya and the whole cremation at the lake/title of the episode ... they have set it up for her to return as the lady of the lake - that is something the producers have confirmed.

I don't know if they get put up on the internet/seen by many people who aren't English but this year they've done a series called 'Merlin: Secrets and Magic' which runs alongside the main show in 15mins episodes and is essentially interviews with cast/crew relevant to that particular episode, behind the scenes stuff etc. This week they talked a lot about Freya and her significance to Merlin and subsequent plots.

Btw ... fantastic (and really interesting!) review.