According to this article, Samsung might be well on its way to using CyanogenMOD 7 on its smartphones. I use a custom CM7 on my HD2 and love it. It can only be a good thing for Samsung phones.
http://pocketnow.com/android/cyanogenmod-in-the-works-for-galaxy-s-ii-thanks-to-samsung
http://pocketnow.com/android/cyanogenmod-in-the-works-for-galaxy-s-ii-thanks-to-samsung