Absolutely, completely, and whole-heartedly second the needing another King Arthur movie (or tv show, or mini series, or anything else, for that matter). But one caveat, can it be a good one?
Not necessarily because others are bad, but because there always manages to be a general mediocrity. Which is truly impressive, if you look at how incredibly divergent and versatile the oeuvre of Arthurian legend actually is (cf. the bizarre way interpretations like the Sword in the Stone, the Mists of Avalon, Merlin, and Monty Python and the Holy Grail all incorporate about the same level of Arthurian legend, albeit in entirely different ways).
That being said, I’d be interested in your opinion and/or ranking of the heavy hitters.