YouTube has long been a thorn in the side of Roku, but that's officially coming to an end.
Roku announced that YouTube is now available on all of the company's current-generation streamers in the US, Canada, UK and the Republic of Ireland. in December of 2013, and the new Streaming Stick was the first device to ship with YouTube from launch.
Roku defines "current generation" as any box the company released after July 2011, which includes, "the Roku LT, Roku 1, Roku 2, Roku 2 HD, Roku 2 XD, Roku 2 XS, Roku 3, the Roku Streaming Stick (both HDMI and Roku Ready versions), and the Roku HD model #2500." While that levels the playing field in terms of app availability, don't expect all of the boxes to perform similarly. In, I found YouTube to boot up pretty sluggishly compared to the Roku 3, and some quick tests with the showed similar performance.
On the upside, all of the boxes will support Chromecast-style control for YouTube, letting you use your mobile device's native YouTube app to "push" content to your TV. It's an especially nice feature for YouTube, where frequent searching really benefits from being able to type on a mobile device versus a clunky onscreen keyboard.