Someone asked my boss's buddy Art Medlar if he was going to buy an iPad. He said, "I figure as soon as it runs Emacs, that will be the sign to buy." I think he was just trying to be funny, but his statement is actually fairly profound.
It's well known that submitting iPhone and iPad applications for sale on Apple's store is a huge pain--even if they're free and open source. Apple is acting as a gatekeeper for what is and isn't allowed on your device. I heard that Apple would never allow a scripting language to be installed on your iPad because it would allow end users to run code that they hadn't verified. (I don't have a reference for this, but if you do, please post it below.) Emacs is mostly written in Emacs Lisp. Per Apple's policy, I don't think it'll ever be possible to run Emacs on the iPad.
Emacs was written by Richard Stallman, and it practically defines the Free Software movement (in a manner of speaking at least). Stallman's vision for the future of computing is very open, and Apple's vision for the future of computing is very closed. Hence, it's ironic that Emacs, which is such a profound part of Free Software history, can't ever run on the iPad.
Hence, I think there's a profound truth when Art Medlar said, "I figure as soon as it runs Emacs, that will be the sign to buy."