Set-top boxes have never been strong on live content, instead focusing their efforts on content available on demand, like the shows and movies offered by Vudu and Netflix. Those looking for the lean-back, channel-surfing experience of traditional TV have been left wanting by set-top boxes thus far. Roku on Tuesday made its first step in the cable direction, announcing a partnership with luxury network WealthTV that will bring 24/7 live streaming to the Roku box.

WealthTV's network features programming about world travel, cars, food, fashion, news and more, all geared toward the wealthy viewer. In addition to the cable channel, WealthTV also features some on-demand content. For $2.99 per month, Roku users can subscribe to WealthTV, and in addition to access to the on-demand library, they will get access to the 24/7 live stream from WealthTV, which will look and function exactly like a cable TV channel.

Though its added audience is a niche one, the implication of Roku's partnership with WealthTV could be significant: as broadband Internet gets faster and faster, streaming live TV is ever more possible, and it's not hard to envision a world in which cable companies broadcast their feed over the Web to be streamed from a browser or gadget, much like radio stations do now.

The a la carte subscription option could be a sign of things to come as well—viewers have been clamoring for quite some time to be able to pay only for the channels they want, and WealthTV and Roku are providing the beginnings of just that. Though Roku might not see a huge uptick in Roku XDS sales thanks to WealthTV, if more popular channels follow the model—which, thanks to long-term deals made with cable companies, could be a challenge—it could finally present a viable challenge to the cable companies' business.