I think you are correct. I was re-watching the keynote and took some screen grabs of Steve demoing with the iPad in both landscape and portrait. If you look at the attached pick, it looks to me like the wallpaper is 1024x1024. So when in landscape a small strip (128 pixels) of the picture on the top and bottom is not visible and when in portrait the strips are on the sides.
Originally Posted by EthicsD
Assuming this is the case it appears that square (1024x1024) images centered on the item of interest will make the best wallpapers. Hopefully we will know for sure soon.
Top row has the captures and bottom is one grab overlaid on the other. (Make sure to look at the image full size :))
Are we absolutely sure that the wallpaper rotates and that there is no possibility of there actually being 2 images? One 768X1024 and the other 1024X768? Anyways there are 100's of iPad wallpapers over at iPad Tablet Central. Check them out!
According to the video below, we will be able to choose different pictures for the lock screen and the wallpaper. It doesn't look like we can choose different ones for portrait and landscape. Things could change though.