Nothing new to the technophiles, but as I recently installed Windows Live Messenger on my work computer, the installer asked if I wanted to install other features. I hadn't heard of these, so I looked them up:
Windows Live Mail = Mac Mail.app (which has been around for years, with the same functionality)
Windows Live Photo Gallery = Mac iPhoto app
Windows Live Spaces = The service formerly known as .Mac, and now (I think) MobileMe, also Yahoo 360 (is that still around?)
Tabbed browsing in IE = Firefox...that's so ~4 years ago
So, not so innovative. At least now I know what all the names mean.