Normally when the battery dies on a gadget, the company replaces the battery for some sort of service charge. Not so with the iPad - Apple is planning on giving you another tablet in its place for $99.
According to Apple's FAQ page on the iPad battery, should something go wrong with your iPad that wasn't your fault (meaning you didn't drop it because you're clumsy with shiny objects), Apple will replace it with a "replacement" iPad with factory settings (meaning all of your saved information and settings are gone).
I assume Apple will refurbish the iPads and re-sell them on their online site to maintain that "green" image and not look like they're just tossing dead gadgets by the wayside. But what they might be shipping back to consumers could be a refurbished iPad, as the FAQ page states "replacement," not "new."
But note that with the $6.95 shipping charge, this will all actually cost you $105.95. I wonder if that can be avoided by taking it straight to the Genius Bar and making the exchange there, as I have done in the past with one of my old iPods.
One of the biggest problems I've always experienced with Apple products (particularly first-gen editions) is poor battery life. I don't know how many times I had my old iPod mini replaced, and like the future iPad, I always received a new iPod mini instead of just swapping the battery out. But that's probably one of the reasons there are no iPod minis left on the market anymore.