Apple and Roku are dominating the IP set top box market, with Apple owning 56% of this still small market segment. I'm not convinced that Apple or Roku will ultimately end up with a major portion of this market, as the total number of households that have converted to OTT is still very small. Rapid market growth in the next several years could let a yet unidentified firm capture a big portion of this. As Blackberry has demonstrated so aptly, having a big marketshare early does not automatically lead to market dominance.
But I've been saying for years that traditional cable TV, and to a lesser extent, satellite TV, is dead, dead, dead. It is an antiquated business model predicated on sixty year old coax technology. And satellite TV uses the same business model over a similarly bandwidth-constrained medium.
But Apple certainly has an early lead, and Google's Chromecast seems to be off to a slow start, but Google can play the long game. And startups like SimulTV may tear off an interesting piece of the market because they have changed the interaction model completely. If companies like SimulTV can master the content license problems, a lot of people will use their services.