Automattic, the parent company of WordPress.com, has released a Windows version of its desktop application. The app is free and works well on my Windows 7 64Bit machine.
It looks and performs exactly the same as its Mac counterpart. This is to be expected as the interface is driven by JavaScript that communicates with the WordPress.com REST API.

It’s worth noting that the desktop apps don’t have as many features as the mobile apps. For example, you can’t moderate or manage comments. According to the development team, this is only the beginning and users can expect to see rapid iteration in the weeks to come.
I’d love to see this on Chrome/ChromeOS as well. I wonder how hard it would be to package it for Chromebooks.