... both for Gtk- as well as for the upcoming Curses- based installers. Then let's ask users at time of install-begin, if the want a setup based on default choices (current installer), or rather if they prefer to explicitly specify as many things as possible themselves.
Both installers should be maintained in parallel. The expert installer will permit the user to make ZFS partitioning choices such as for the swap volume size, one or more mirrored or non-mirrored pools, how many zfs filesystems or volumes, which mountpoints etc. It also follows Moinak's advice how to handle Dual-Boot configs of different OS'es, whether on the same physical HDD or on several physical HDD's with a shared Grub menu, pkg cluster choices etc. -- %martin
