If you have a Jailbroken IPhone and IPad can you still update them?

I have both a jail broken iPhone 4 and a IPad 3 and I got a notice from at&t by text saying that an upgrade is available. I have IOS 5 in both devices now. What will happen if I update to IOS 6 via the iPhone and iPad even though it's a jail broken device? Will it hurt the device? I want to upgrade, but I want to keep the jail break, so how do I do both safely? I would prefer not to restore either devices because I have run into major problems in the past trying to restore and become very frustrated.

It will probably freeze it. But maybe whatever website you got the jailb. From might have an update installer.

Ell the jailbreak is made for 5.x.x so the different code will mess it up
so must restore to 6.0 and do a jailbreak when one is made for ipad 3