Anyway, style does matter and were this line written with readability in mind you wouldn't make this mistake.

Also, I would definitely abstract over @get and property:

    makeProperty = (attrs...) -> 
        func = () -> (@get(x) for x in attrs).join(" ")
        func.property(attrs...)

    MyApp.president = Ember.Object.create(
        fullName: makeProperty("firstName", "lastName")
    )