[Defy Android Development] fritolays:
Ya you would have modify the updater-script to look at least something like:

ui_print("Welcome to CyanogenMod-6.1.2-0.07-11.01.28-Milestone!");
package_extract_file("system/bin/backuptool.sh", "/tmp/backuptool.sh");
set_perm(0, 0, 0777, "/tmp/backuptool.sh");
run_program("/tmp/backuptool.sh", "backup");
show_progress(0.500000, 0);
format("MTD", "system");
mount("MTD", "system", "/system");
show_progress(0.500000, 40);
package_extract_dir("system", "/system");
symlink("busybox", "/system/xbin/[", "/system/xbin/[[",
"/system/xbin/arp", "/system/xbin/ash", "/system/xbin/awk",
"/system/xbin/basename", "/system/xbin/bbconfig", "/system/xbin/brctl",
"/system/xbin/bunzip2", "/system/xbin/bzcat", "/system/xbin/bzip2",
"/system/xbin/cal", "/system/xbin/cat", "/system/xbin/catv",
"/system/xbin/chgrp", "/system/xbin/chmod", "/system/xbin/chown",
"/system/xbin/chroot", "/system/xbin/cksum", "/system/xbin/clear",
"/system/xbin/cmp", "/system/xbin/cp", "/system/xbin/cpio",
"/system/xbin/cut", "/system/xbin/date", "/system/xbin/dc",
"/system/xbin/dd", "/system/xbin/depmod", "/system/xbin/devmem",
"/system/xbin/df", "/system/xbin/diff", "/system/xbin/dirname",
"/system/xbin/dmesg", "/system/xbin/dnsd", "/system/xbin/dos2unix",
"/system/xbin/du", "/system/xbin/echo", "/system/xbin/ed",
"/system/xbin/egrep", "/system/xbin/env", "/system/xbin/expr",
"/system/xbin/false", "/system/xbin/fdisk", "/system/xbin/fgrep",
"/system/xbin/find", "/system/xbin/fold", "/system/xbin/free",
"/system/xbin/freeramdisk", "/system/xbin/fuser", "/system/xbin/getopt",
"/system/xbin/grep", "/system/xbin/gunzip", "/system/xbin/gzip",
"/system/xbin/head", "/system/xbin/hexdump", "/system/xbin/id",
"/system/xbin/ifconfig", "/system/xbin/insmod", "/system/xbin/install",
"/system/xbin/ip", "/system/xbin/kill", "/system/xbin/killall",
"/system/xbin/killall5", "/system/xbin/length", "/system/xbin/less",
"/system/xbin/ln", "/system/xbin/losetup", "/system/xbin/ls",
"/system/xbin/lsmod", "/system/xbin/lspci", "/system/xbin/lsusb",
"/system/xbin/lzop", "/system/xbin/lzopcat", "/system/xbin/md5sum",
"/system/xbin/mkdir", "/system/xbin/mke2fs", "/system/xbin/mkfifo",
"/system/xbin/mkfs.ext2", "/system/xbin/mknod", "/system/xbin/mkswap",
"/system/xbin/mktemp", "/system/xbin/modprobe", "/system/xbin/more",
"/system/xbin/mount", "/system/xbin/mountpoint", "/system/xbin/mv",
"/system/xbin/netstat", "/system/xbin/nice", "/system/xbin/nohup",
"/system/xbin/nslookup", "/system/xbin/ntpd", "/system/xbin/od",
"/system/xbin/patch", "/system/xbin/pgrep", "/system/xbin/pidof",
"/system/xbin/ping", "/system/xbin/pkill", "/system/xbin/printenv",
"/system/xbin/printf", "/system/xbin/ps", "/system/xbin/pwd",
"/system/xbin/rdev", "/system/xbin/readlink", "/system/xbin/realpath",
"/system/xbin/renice", "/system/xbin/reset", "/system/xbin/rm",
"/system/xbin/rmdir", "/system/xbin/rmmod", "/system/xbin/route",
"/system/xbin/run-parts", "/system/xbin/sed", "/system/xbin/seq",
"/system/xbin/setsid", "/system/xbin/sh", "/system/xbin/sha1sum",
"/system/xbin/sha256sum", "/system/xbin/sha512sum",
"/system/xbin/sleep", "/system/xbin/sort", "/system/xbin/split",
"/system/xbin/stat", "/system/xbin/strings", "/system/xbin/stty",
"/system/xbin/swapoff", "/system/xbin/swapon", "/system/xbin/sync",
"/system/xbin/sysctl", "/system/xbin/tac", "/system/xbin/tail",
"/system/xbin/tar", "/system/xbin/tee", "/system/xbin/telnet",
"/system/xbin/test", "/system/xbin/tftp", "/system/xbin/time",
"/system/xbin/top", "/system/xbin/touch", "/system/xbin/tr",
"/system/xbin/traceroute", "/system/xbin/true", "/system/xbin/tty",
"/system/xbin/tune2fs", "/system/xbin/umount", "/system/xbin/uname",
"/system/xbin/uniq", "/system/xbin/unix2dos", "/system/xbin/unlzop",
"/system/xbin/unzip", "/system/xbin/uptime", "/system/xbin/usleep",
"/system/xbin/uudecode", "/system/xbin/uuencode", "/system/xbin/vi",
"/system/xbin/watch", "/system/xbin/wc", "/system/xbin/wget",
"/system/xbin/which", "/system/xbin/whoami", "/system/xbin/xargs",
"/system/xbin/yes",
"/system/xbin/zcat");
symlink("toolbox", "/system/bin/cat", "/system/bin/cmp",
"/system/bin/date", "/system/bin/dd", "/system/bin/dmesg",
"/system/bin/getevent", "/system/bin/getprop", "/system/bin/hd",
"/system/bin/id", "/system/bin/ifconfig", "/system/bin/iftop",
"/system/bin/insmod", "/system/bin/ioctl", "/system/bin/ionice",
"/system/bin/kill", "/system/bin/log", "/system/bin/lsmod",
"/system/bin/mkdir", "/system/bin/nandread", "/system/bin/netstat",
"/system/bin/newfs_msdos", "/system/bin/notify", "/system/bin/printenv",
"/system/bin/ps", "/system/bin/reboot", "/system/bin/renice",
"/system/bin/rmdir", "/system/bin/rmmod", "/system/bin/route",
"/system/bin/schedtop", "/system/bin/sendevent",
"/system/bin/setconsole", "/system/bin/setprop", "/system/bin/sleep",
"/system/bin/smd", "/system/bin/start", "/system/bin/stop",
"/system/bin/sync", "/system/bin/top", "/system/bin/uptime",
"/system/bin/vmstat", "/system/bin/watchprops",
"/system/bin/wipe");
set_perm_recursive(0, 0, 0755, 0644, "/system");
set_perm_recursive(0, 2000, 0755, 0755, "/system/bin");
set_perm(0, 3003, 02750, "/system/bin/netcfg");
set_perm(0, 3004, 02755, "/system/bin/ping");
set_perm(0, 2000, 06750, "/system/bin/run-as");
set_perm_recursive(1002, 1002, 0755, 0440, "/system/etc/bluetooth");
set_perm(0, 0, 0755, "/system/etc/bluetooth");
set_perm(1000, 1000, 0640, "/system/etc/bluetooth/auto_pairing.conf");
set_perm(3002, 3002, 0444, "/system/etc/bluetooth/blacklist.conf");
set_perm(1002, 1002, 0440, "/system/etc/dbus.conf");
set_perm(1014, 2000, 0550, "/system/etc/dhcpcd/dhcpcd-run-hooks");
set_perm_recursive(0, 2000, 0755, 0750, "/system/etc/init.d");
set_perm(0, 0, 0755, "/system/etc/init.d");
set_perm(0, 2000, 0550, "/system/etc/init.goldfish.sh");
set_perm_recursive(0, 0, 0755, 0555, "/system/etc/ppp");
set_perm_recursive(0, 2000, 0755, 0755, "/system/xbin");
set_perm(0, 0, 06755, "/system/xbin/hcitool");
set_perm(0, 0, 06755, "/system/xbin/librank");
set_perm(0, 0, 06755, "/system/xbin/procmem");
set_perm(0, 0, 06755, "/system/xbin/procrank");
set_perm(0, 0, 06755, "/system/xbin/su");
set_perm(0, 0, 06755, "/system/xbin/tcpdump");
show_progress(0.200000, 0);
show_progress(0.200000, 10);
package_extract_file("system/bin/backuptool.sh", "/tmp/backuptool.sh");
set_perm(0, 0, 0777, "/tmp/backuptool.sh");
run_program("/tmp/backuptool.sh", "restore");
show_progress(0.200000, 10);
show_progress(0.100000, 0);
unmount("/system");

Removing the assert checks (because its not a milestone); and the part where it flashes a new boot.img (again not a milestone).

But it probably wont work; simple looking at the files it replaces, I doubt it would get past the M logo.