Alternatively, for those who want good-looking text but prefer the WYSIWIG approach: just use a half-decent DTP program like InDesign, which will get you everything mentioned in the article except for the per-character transparency.
Do you think anyone will still be able to open your documents in Adobe InDesign 200 years from now? This may not matter to everyone, but if it matters for your purposes, LaTeX has a clear advantage here.
EDIT: I'm not affiliated with the author of this article.
The ability to split a document in multiple source files and having SVN/git/etc makes it really easy to work on the document at the same time.
Mac OS X’s font palette (while sucky in general and in dire need for a makeover to improve its UI — it’s like vintage 2000 or so) also offers you many of the mentioned features: 1 and 3 are on by default everywhere (type ‘shuffle’ into the Spotlight searchbox, ‘ffl’ will be turned into the appropriate ligature), 2, 4 and 5 are accessible through the palette but I don’t think OS X is clever about line-breaks (at least there are no settings to fine-tune). Don’t know about transparency. It is available to you in every program which uses OS X’s standard method of text input (like Pages or Safari).
You could retrofit smart justification onto the text system, but it would require some non-trivial code (namely an NSTypesetter subclass). It's not easy, but it's possible.