Your warranty is only void if you were foolish enough to take the device back to the Apple store obviously jailbroken and ask for a repair.
Connecting any jailbroken iPad to iTunes and pressing "restore" will also restore your warranty as if by magic. At least, by the same magic with which Apple miraculously voided it when you jailbroke

A restored iPad has no trace anywhere on the device that it was once jailbroken. Even with broken hardware it is possible to mask the jailbroken status of a device. If anyone ever gets into that situation we can easily help them here.
I am the first to admit that jailbreaking is not for everyone and folks should be free to choose what to do for themselves, but in my 5 years of jailbreaking devices I have yet to discover anyone who actually fell foul of the "voided warranty" scaremongering which surrounds the jailbreak.