If you buy an iPad and the battery conks out, Apple will replace it with a new iPad, Apple says on a web page called "Battery Replacement Service" (http://www.apple.com/support/ipad/service/battery/).
According to the page, if your iPad requires service due to the battery’s diminished ability to hold an electrical charge, Apple will replace your iPad for a service fee. The service costs $99, plus $6.95 shipping. The total cost is $105.95 per unit.
However, Apple notes: Your iPad is not eligible for Battery Replacement Service if the product has been damaged, for example, as result of an accident, liquid contact, disassembly, unauthorized service or unauthorized modifications, or if the product is not operating correctly as a result of a component failure."
iPad is now available for pre-order. They're due to ship on Saturday, April 3....