Beyond that, there's as little to go on as there was in the scraps of my previous Arthurian article. Variety notes that it will be a "re-imagining" of the Arthur myth, but that it's drawing on Sir Thomas Malory's Le Morte d' Arthur. This 15th century collection of tales has been the basis of just about every Arthur story to date, including John Boorman's Excalibur. You can get a little rundown of all the tales on good old Wikipedia, although I recommend buying a copy sometime if you really dig going to the source. They've survived from the 15th century for a reason.
So, the big question will be how this version will re-imagine Malory, and how it's going to contrast with Bryan Singer's Excalibur remake that's also at Warner Bros. I like Ritchie for the job, though. He loves England, and I thought Sherlock Holmes really showed a knowledge of Sir Arthur Conan Doyle, and a love of London extended beyond Ritchie gangsters and into a fantasy Victoriana. If he could bring that to the Middle Ages, keep the magic and bromance, and make it look like the sweeping, Pre-Raphaelite vision that many of us cherish, it would be the perfect King Arthur movie.
What do you think?