Following up on this actual attempt by some British to revise the Ten Commandments, Ophelia Benson has begun a list of her own. Of course, being a confirmed atheistic skeptic, she's not takng the exercise quite as seriously. Frankly, as a believer, I find the exercise (or at least the reported results) kind of embarassing.
Two comments: first, of all, if you're going to revise the Big Ten, it seems like a good guideline would be to keep the number at ten, taking something out for everything new that gets put in. Though, to be fair, the Big Ten are actually a small part of the Original 613, so there's some room to play around, I guess. Second, Benson's coming up with stuff that's no worse than the religious folks (and actually might be more thought-provoking and useful, in the long run).