[mindfrost82]

Just like other Android phones, it will let you install apps that require root access, like the wifi tether app in the Market (assuming it works with the Galaxy).

Eventually, it will hopefully let you install custom ROMs, but that's more dependent on the Recovery being unlocked.

Assuming someone starts creating kernels for you, you could potentially overclock it as well.

It might also give you the ability of using a different launcher and getting rid of TouchWiz.