It is possible, however I've yet to get it working (completely). I have been using Type Fresh, since it seems like the easiest way. The first time I changed the fonts and rebooted, it worked okay. I decided to change them again, but this time when it rebooted it never got past the white "htc EVO 4G" screen. I wiped my device and cache, re-flashed the ROM and tried again, it froze again when rebooting. I'm too tired to continue on tonight, but I'll keep trying tomorrow after I make a new nandroid backup.
Using Fresh 0.5.3