The official specification of border-image (see URL) has been drastically revised since the Firefox 3.5 implementation was frozen. Please add a warning to the -moz-border-image page on devmo, saying that both the syntax and semantics of border-image are likely to change in future releases of the browser, and specifically discouraging use of the optional border-width override (which has been taken out).
I've added an appropriate warning to the article here: https://developer.mozilla.org/En/CSS/-moz-border-image
Thanks! I changed "HTML 5" to "CSS 3" but otherwise it looks good.