Word is still a great Word processor. It actually has a full screen mode that eliminates all the distractions just as the programs used by the author. Word's biggest problem is that all its power increases its complexity and there really isn't a good user manual or resource to train people. I find that most people that switch to something like GoogleDocs don't use the advanced features of Word and probably would have been just as happy using WordPad.

What would be 'advanced features' of Word that are neither completely unnecessary nor could be replaced by (more or less) simple LaTeX macros?

I'm actually curious - I've heard a lot of people raving about the 'power of MS Word', yet no one was really able to name any meaningful features that would justify calling it 'powerful'.

I use LaTeX for most of my writing, and I'm not a big fan of Word. That being said, I think the advantage probably is that it significantly lowers the barrier of entry to those advanced features. Hence, you'll get 'secretaries' doing fancy stuff, who might not be otherwise inclined to learn LaTeX (and let's admit it, writing TeX macros is not particularly nice).

I have to admit I haven't learned LaTeX myself yet, but I've been using LyX for a while now, which basically spits out compilable TeX. Processors like LyX (are there even any processors like it?) take care of exactly that barrier of entry.

I agree fully that advanced features in LaTeX are most likely more difficult to learn, but if the argument in the first place is the 'power' of the features, then LaTeX will win out regardless. It's like comparing vim/emacs to nano (in terms of 'power').