also...
 
What do you see as the benefits of translating into a javascript PRDocument type structure?

I guess it would make more sense to use a neutral format ie javascript version of PRDocument if Pier would ever support other wiki formats such as Markdown [1] or Google wiki syntax [2]

[1] http://en.wikipedia.org/wiki/Markdown
[2] http://code.google.com/p/support/wiki/WikiSyntax