[Martijn]

Currently addons are totally dependant of the current used skin for the used fonts.
So this means even though they can create their own custom skin for this specific addon there is no way for them to specify custom fonts.

Example of one is this:
Spotimc
http://forum.xbmc.org/showthread.php?tid=125147

now it needs to hack the skin code to add the custom fonts which is one of the rules why we can't allow it to be in repo.
Somewhere in the Spotify API rules it mentioned that it needed to use a specific font (although this might have changed already).
It would be great if this would be possible by the time of Helix release so we can get these legal services into our repo. I'm sure a lot of people would love to have this.
Of course this will also benefit other addons

[Ned Scott]

This would be awesome. I don't know much about add-ons, I learned about this when I was trying to help/encourage a guy to make a clock screensaver add-on. It was his first XBMC add-on and we looked all over the documentation on how to make the text of the clock bigger and quickly learned that the add-on was limited to the defined options by the skin. He eventually did something using images instead of text, but something like this would have greatly simplified his task.

[Kib]

I worked on that clock add-on with him. Was indeed an issue there as well.