The latest rumor from this piece on Electonista is that Samsung may soon roll out a firmware update for the Tab that would clamp down on rooting and custom firmwares. Apparently the new JM6 A, C and D builds Samsung are to have bootloaders that are signed which would prevent unauthorized firmwares. Once this new firmware is installed, any jailbreaks, roots and other custom firmware won't run. I think most users don't care about custom firmware but a lot of users root the device to remove the carrier crap-ware.
Something to think about as the updates for the Tab come out! A lot of people bought the Tab because they wanted a tablet they could control and not fight Apple at every turn. This firmware update could prove to be more difficult to break than Apple products (ironic eh?)