Some additional information on this:
For the built-in commands into the browser's rich edit engine (e.g. commands such as Bold, Italic, FontName, FontSize), the editor relies on using the built-in document.queryCommandValue
function to obtain the current state - as it "expects" that this built-in function would return the most accurate information even in more complex scenarios.
While in IE the queryCommandValue returns "Verdana" correctly, in FF the browser returns an empty string.
Of course, when the user has actually applied explicitly some font styling using the tool, then the information returned is correct.
the Telerik team