actually you could end up having 5:
-o-superstyle
-webkit-superstyle
-moz-superstyle
-ms-superstyle
superstyle /* for new versions released after standard becomes stable */
And only if no more new browsers appear.
-o-superstyle
-webkit-superstyle
-moz-superstyle
-ms-superstyle
superstyle /* for new versions released after standard becomes stable */
And only if no more new browsers appear.
My opinion is that the only problem is that the vendor prefix for border-radius was dropped too late.