If you restore it in iTunes which is very quick/easy then it will be back to normal with no traces of the jailbreak, it's if something happens and you can't restore it I.e the screen breaking and you can't see to actually restore it, they wouldn't fix it then. Be very unlucky if something like that happens though.

The misses got an ipad2 just before Xmas, we got a back case and a little sleeve type case to put it in when it's not in use.