Well i just finished watching this episode and.... it was good.
The acting as usual was great.
There were two problems i had with it.... it was predictable... i knew it was going to be Lancelot. I mean, we all know that Arthur's time is nowhere near and Merlin is the main man... so he also would not have died. The only persons that actually knows Merlin's secret is Gaius and for a while now Lancelot, whom has gotten to know Merlin so much more in this episode and has came to the realization that he could not allow Merlin to sacrifice himself because he plays the most important role of keeping Arthur safe than anyone else he knows and not to mention he gave Gwen his word to protect Arthur.
The other problem is that.. i was expecting even a little physical confrontation between the evil witch and Merlin.... two powerful sorcerers meets and nothing.... Arthur walks up to sacrifice himself, Merlin stops him and as Merlin was about to sacrifice himself, Sir Lancelot took his place.
You will be missed Sir Lancelot... a brave knight, a honest and noble friend and a true man of his words.