The first was You Tube, that anounced they will start offering full HD streams (1080p). So far, You Tube has an HD option with a resolution of only 720p. To understand the difference, check this wiki entry.
Next is Boxee. This company will launch a Boxee box that will enable web content to be delivered into your TV. Another possibility is to buy the new Dell Mini Desktop computer and connect it directly to the TV.
Now that you have Internet TV in your, well, TV, you need a nice programming guide. Look no further: Clicker has the solution.
Cable companies, be afraid. Internet TV is looming.