The Forecast Channel is a lot like Google Earth and it was the first thing I thought of when I saw a preview video for it online before. You can do extreme zooms in and out of the world, shift the aerial view, and rotate the world in a fashion very similar to Google Earth.
The internet channel isn't out yet (one more day!), but from what I've seen on preview videos, when you click any typing bar, a window will pop up with a keyboard and you click on the letters/numbers/symbols that you want to type. I wonder if you can plug in a USB keyboard into the Wii and use it for stuff like that?