The one big scene had all the knights, plus Merlin and Arthur, and is very sweet - Merlin is basically goading Arthur into fighting knight after knight, just to prove he can do it. "I'm the whole package!" Arthur declares. "Mmm," says Merlin, "Gawaine. Now he's the whole package." "Gawaine! Pah. Gawaine has the attention span of a new born lamb!" Arthur then proceeds to fight Gawaine to prove it to Merlin, and so it goes on :) It was a scene full of fan service, including Gawaine fighting shirtless for no apparent reason (except to distract Arthur perhaps!)
Finally Arthur fights Elyan with axes, the head of the axe flies off and Elyan keeps going, declaring, "Merlin can't save you now!" while Arthur's shouting "Merlin! A spare weapon! MERLIN!" and Merlin ignores him :)
The big spoiler now... Arthur is called the King in this scene. This is episode 6. Oooh.