This is a magnificent program. I LOVE the solid interface and options.
One key element will put this over the top for me is this. I am a graphic designer who always likes to view my headlines in different faces. I utilize the font faces view a LOT. The Three "Font Face Text Sample" customizable presets are nice. But this suggestion would enhance that function even more.
Pleeze integrate a Hotkeyable function that instantly updates the "Font Face Text Sample" with the clipboard contents. This allows users to immediately preview the specific text that they want.
Also if a Text input field can be put on the toolbar that updates the same "Font Face Text Sample" that would be nifty and VERY convenient especially if you could type a hotkey to highlight the field, type your text, hit enter and bam!
Basically the (custom hard coded) samples in the options menu is a great feature, but lets make it accessible to users from the main interface instead of 2 levels down (in options) for a function that is heavily utilized.