The odd thing is, that is actually how it's always been functioning.  Test "font-size" or any other css property name and it'll give you the proper value; try it with the javascript name property and you'll get undefined or an empty string. I believe this is because in enyo.dom.getComputedStyleValue, you return the value of s.getPropertyValue(inProperty), which by definition uses the css property name. If you wanted the javascript property name, you could just reference s[inProperty].

Personally I like the current css property name format, as it's similar to other existing styling formats used by enyo.Control, such as applyStyle and addStyles.

Do note: if you do change to use the javascript property name format, the polyfill would still be compatible and work :)