That'll be great. Currently there are services like Amazon instant video,Vimeo, Rdio, Spotify, Put.io are not on chromecast. They usually have Smart TV apps but Chromecast can be the new de facto of TV app development.
In addition, your chromecast MUST be connected to the internet to play anything (not just local lan, must have actual internet access). Maybe they are planning on version2 showing ads when nothing else is playing or something. Who knows.
My chromecast now sits unused in some drawer somewhere.
Thankfully the Plex app will not require the Plex Pass soon.