This is great stuff! Thanks for the info ei8htohms!
Kind of reminds me of the days changing the fonts on the Razr's.
One thing that was kind of odd that happened.
When I did the line mount -o ro,remount /dev/mtdblock4 /system
the phone restarted on it's own, I didn't even get a chance to type sync, reboot.
I'm using Better Terminal Emulator Pro, don't know if this makes any difference or not.
But everything turned out fine and the new fonts are in.
This can absolutely be done in the terminal, but if something goes wrong (you delete the primary font and your phone magically reboots for instance) you will be effectively bricked without ADB. If the base font (DroidSans) is found to be incompatible or missing altogether then the phone won't even boot, so without a recovery image with a terminal option, you won't even be able to turn on the phone, see?
For this reason, I'm not about to encourage someone who doesn't know how to use ADB to try this mod just yet. As soon as a recovery image with terminal, Nandroid or some other recovery options is available I'll update the original post with other instructions.