You can go under displays and goto the option where it shows both screens and you can click on the white bar at the top of the one screen and move it over to the other to make that the primary screen, or you can click "Mirror Display" and it will mirror them but one will suffer depending on the support resolutions. The way you have it is you have two desktops, you should be able to move app screens over to the other screen by dragging them...but you have to set the orientation in the "Display" dialogue first so if your TV is on the left, you move your mouse to the left of your screen to move to the TV screen. And what I meant by resolutions is my 26" HD tv doesnt support the same resolution as my MBP so when I mirror the displays the MBP display gets smaller, doesnt fill the screen, and switches to a lower resolution.
