Today Amazon announced that YouTube is now available on all Fire TV models. A few weeks ago YouTube started to roll out to some Fire TV devices but not the 1st gen Fire TV Stick or the Fire TV boxes. Today YouTube is available on all Fire TV devices with the addition of the Fire TV Stick (1st Gen), Fire TV (1st Gen), Fire TV (2rd Gen), Fire TV (3rd Gen). Sadly no date on when YouTube TV and YouTube Kids will come to the Fire TV. Amazon is still saying sometime this year for both YouTube TV and YouTube Kids.
Amazon Updates The Fire TV to Add YouTube to All Fire TV Devices