Well, one could just use the existing CSS/HTML combo and make it happen too. I think that would bode not only better for users (imagine a similar look and feel), but then creators would really have a better control of multiple formats via a one shot deal.
Check out this site:
http://www.alistapart.com/articles/boom
While I personally wouldnt care for the step that takes it into PDF format, the fact that CSS/HTML already allows for this makes for a neat one step solution for those looking to publish electronically, as well as in print.