This looks cool. Pro tip! Make iPad backgrounds in 1024 x 1024. That why it handles being rotated well. It will clip it to match the 1.333 aspect ratio of the screen by either cutting off the right and left when vertical (portrait mode) or the top and bottom with horizontal (landscape mode). Makes it look slick, especially if you can plan for it and incorporate it into the design.

Here is a file to help! http://goo.gl/UdJYW

The purple/pink part is what will normally be visible depending on orientation. The blue corners are what show only when rotating.

Dude. Nice. :)