Ian Hickson writes interesting stuff about the evolution of companies. One quibble: what he describes is "evolution" only in a very loose sense. Evolution, even non-biological evolution, generally requires reproduction with heritable characteristics that affect fitness, and that doesn't seem to be present here. All we have here is adaptation IMHO.
That aside, he's basically right: people have learned to adopt business models that can't easily be crushed by Microsoft, but they all have the weakness that a superior Microsoft product would hit them hard.
He omits, though, that there are other things Microsoft could do (and is trying to do) that would also hit their competitors hard --- for example, patent assaults. And open-source isn't as immune from a cut-off-their-air-supply attack as I think he makes out.