I love this idea. When I first started using LJ, I didn't know any html and I had to have the help cheat sheet open all the time. While I am glad that I learned it, I think it would make DW appeal to a broader range of people who would really contribute in valuable ways to the community. Additionally, I think it would make the site more accessible and accessibility is important. Requiring someone to learn html formatting can be an impediment to people who have trouble learning new things. (I'm specifically thinking about problems like multiple sclerosis and brain injuries but everybody's brain is different and learning computer language can be impossible for some people.)