Probably old news to most SEOs, since I dont bother with MSN all that much, the idea that on-page optimization is king for MSN is news to me. This serp seems to confirm it, where the page that repeats keywords 11 times ranks the highest among all other types of optimizations.
Looking at my test pages, results are like night and day on MSN and Google. I guess I should really build 3 different sites running on the same database for 3 search engines, which is actually ridiculously easy do, except building incoming links — that would be the hard part, to split links among three versions of the same site. But it would make sense at least in the short term to build a site specifically targetting MSN.