The reason that I'm excited about Haiku: a fledgling open-source OS that isn't based on the Linux kernel. It has been awesome to see Linux find its place on the desktop and mobile, yet, the homogeny is rather stifling and it's disappointing to see there's no alternative to maintaining UNIX's legacy (X11, filesystem layout, my personal dislikes). Haiku seems to have the potential to fill that void.
