User blog comment:Uncleho/Perhaps this is how Arthur learns of Merlin's magic?/@comment-77.237.107.152-20121118173353

I dont think that Arthur will find out about Gwen at all, let alone Merlin...First Arthur has to find out that Gwen is a traitor and that she POISONED him...That would be betrayal No2 (No1 -Lancelot) from Gwen, even Arthur would not be so forgiving and we would loose the queen again. Second, if he found out Gwen is enchanted, he would see and strenghten his belief that magic is evil. And third, after all that, Merlin has magic, another betrayal, he could not stand all that...I believe...I also dont want that Arthur goes trough all that, and dont want it to be the way to find out Merlin is magic.

I do think they are keeping the magic reveal for finale, like Morgana18 said.