Welcome to MobileRead, avar!
And congrats on the new Reader.
The present answer is "no" -- there was a way to replace the fonts on the 500 model (which is how to do what you're after), however the efforts to figure out how to do this on the 505 are currently stalled, pending the first 505 firmware update. After that happens, it should be possible to change the fonts on the 505.
