Here's my view of why Windows user won't move over to Ubuntu. See this as a list of what-need-to-be-done list.
* TV-out. It must be easier to watch a movie on your computer via TV-out.
* ICQ. File transfer has to work! Reading other peoples NA and Away message.
* Instant messaging. Miranda IM (with all, or a some of it's plugins) must be avalible for Linux!
* It must be easier to install a FTP server.
* Printing. More options when you'll print. Like, print on both pages, scale and print in "black and white only"