Hmm, reStructedText / rst is looking to be very interesting the closer I look at it — maybe the next best thing to Plain Old Documentation / POD.
I could see this stuff possibly displacing a major chunk of my use for LaTeX and troff, since I have little need for typesetting mathematics or other complex stuffs (think troff p*-processors), it could be quite valuable! Of course, I would have to mate it with the m4 macro processor (or roll my own, or just abuse and filter the C Pre Processor hehe) to get exactly what I would want, but hey, it would work pretty nice!
It would have one chief advantage over LaTeX, not even the people I have to share documents with on occasion, could foul it up toooo badly… lol.