Doh, didn't see this before now - thought I had enabled email notifications of all posts in the fSekrit subforum.
Well, as it is now it's already possible to change the used font - but it requires manually editing the registry, and isn't saved per-note. I've considered the font selection dialog for a while, but there's been more pressing issues to fix first. But I can probably take a look at font selection dialog soon - not sure if I want to save the font per-note though, I'd rather prefer to keep it as a system/per-user setting.
I do, eventually
, plan on making the container format a bit more flexible though, then it'd at least be possible
to save things like font information per-note... right now, that would be another hacked-in thing