NWE2 is, functionally, much closer to being that elusive FrameMaker Mac replacement that I've been hunting for. Based on my own use of FM to write books, these are the only major features missing:
(1) A decent autonumbering system, comparable to FM's, which would permit (a) automatic generation of boilerplate like Warning: at the head of a para that uses the Warning style; (b) automatic numbering of numbered lists; (c) automatic generation of Figure s.n at the head of a Caption paragraph -- where s is the section (chapter) number, and n increments through the text in reading order, but resets at a section boundary.
Side note: please don't try to emulate the Word autonumber system, the way Mellel has done.
(2) A method of cross-referencing, so that the writer can quickly and intuitively create a reference like See 'Abstruse Topic' on page 87 -- and have the reference maintained automatically when the referenced heading is edited to 'Arcane Matter' and moved to page 189.
(3) A method of picking up the most recent head(s) of some level(s) as text in the running page header/footer -- see the NWE2 user manual for an example of this page format. Every page has the most recent chapter and head-1 strings in its header. (Either NWE has undocumented features or they used something else to write that book.)
These three blocks of functionality would make it possible for the writer of simple books and reports to finally move away from FM in Classic mode.
If anybody at Nisus cares, I've written a high-level functional spec that details what I modestly think is a simple and robust way in which these goals could be accomplished... too boring for here, but you have but to ask...