The only thing new about Kodi is the name. It has been around for a long time as XBMC.Kodi is the new Napster for movies?
Not sure where you got that idea that it was like Napster from what I posted? It is a media app that is available on multiple platforms that, off the shelf, gives you access to several native apps (Cnet, Twit, Youtube, etc.) and your own media files that you have on your own network.
http://kodi.tv/about/
XBMC/Kodi has been a hobby for some people because it is open source. I have no idea if it is capable of Napster-like features, but if it is, it is no more a Napster for movies than a PC is a Napster for movies. In other words, just because something is possible on a platform doesn't mean it is meant for that specific purpose. For example,the AppleTV2 isn't meant to run Kodi, but it can if you jailbreak it.