How do you mostly use your touchpad?
I personally use it in Portrait 99.9% of the time. I think it better resembles a piece of paper, which I like. In fact, I really hate widescreen tablets for that reason. The android tablets all come in a widescreen form factor that makes it incredibly uncomfortable to use it in portrait mode. That's why I was so glad that the TouchPad was made with the same ratio as iPad. That's the way to go, I think.
I only use it on landscape for games (i have to) and writing memos because I like to type on the landscape keyboard.