Microsoft is trying to thread the needle here, and this is about as good as they can make it, I think.

Office is a potent club to get them in the tablet game, particular with business, but they take the chance of having other suites put a knock on it if they don't make it available elsewhere.

Apple and Android have what, 90% of the phone market? And 90% of the tablet market? Microsoft can hold out for some finite amount of time, but at some point there will be enough users using other softwares that Word, or Excel, or whatever become "just another" (albeit still important.)

So they make Office available first on their own platform, and then make it available on others, and relentlessly upgrade their own first, trying to keep that Office halo, while still not losing the near-monopoly user base that they garnered a couple decades ago.

I don't know if it's a winning strategy, but I'm not sure they have a choice. To ignore the fastest growing segments threatens the ubiquity of the suite, to hand it over tomorrow diminishes one of the most potent weapons they have to gain acceptance in tablets.

It'll be interesting.