Hi Paul-
My take on this is that Knol is basically Google's attempt to
co-opt/supplant Wikipedia. (Good luck with that, guys.)
As for the equation editor specifically, I haven't used it myself, but
it looks like it would be moderately useful-provided your target
document groks LaTeX, e.g. an actual LaTeX document, or an HTML document
using jsMath (
might be able to hack the guts of Arbortext to make it load and
understand the LaTeX macros, but doin...