This is another neat change that's come as a result of modders realizing that metamorph easily uses su permission to change files to read only and then push data to various parts of the ROM.
This app lets you choose any of the 21 fonts and it gets pushed to all aspects of your phone.
http://forum.droidmod.org/index.php/topic,396.0.html
You'll need to be rooted and have metamorph (available from the market).