Nope, like many other Apple apps, this is only for OS X. I use both a Mac and a PC, and I'd love to see this come over to windows, but I'm under no illusion - it will never be there.
I'll just throw in that there's a jailbreak tweak (Remote Messages) that accesses your iPhone's Messages app via a PC or Mac web browser as long as they're on the same local network. You can do iMessage and SMS that way.