Just came across this: Popular .NET code documentation generator, NDoc 1.3 has been released. It spots an overhauled HTML Help 2 documenter, new code commenting tags, additional attributes support, custom tags, enhanced UI, better performance, and improved output consistency with MSDN topics.
With the new preliminarytag, now we can have the following default message appearing in the docs:
[This is preliminary documentation and subject to change.]
...much like those appearing in the beta MSDN docs of VS 2005. Too bad though, support for .NET framework 2.0 is lacking.