>And now, with 'office on the web', you can use basic office everywhere. (even on Debian)

office is a tiny, almost negligible, piece of the puzzle. quickbooks, solidworks and other cad software, bespoke software, security software, user management, permissions management (replacing active directory), contractual obligations, the millions of dollars required in implementation, the millions more dollars required for increased user support, and so on...

but, again, just to reiterate: i am disputing that windows is in "significant danger" today.