If you really want to get crazy you can PORT Android onto an iPad, well not yet, but you can do that to an Iphone 3gs and I'm sure iPad soon. Not really much help, but it is interesting.

For what you want I suggest a new Mac Book Air with the external Mac Book Air Super Drive. Pricey but has you covered. Air also don't need to come out of luggage, it is light, and has a keyboard.