Apple Boot Camp Website said:
Boot Camp Beta is preview software licensed for use on a trial basis for a limited time. Do not use Boot Camp Beta in a commercial operating environment or with important data. You should back up all of your data before installing this software and regularly back up data while using the software. Your rights to use Boot Camp Beta are subject to acceptance of the terms of the software license agreement that accompanies the software.
Did you read the terms of the software license agreement that you are supposed to read when installing it?
I'm pretty sure it will NOT void your warranty, however they will not provide support for Boot Camp. Meaning if something goes wrong, it is not their problem to fix. But as far as the hardware being voided, I do not think that is the case.