...is pretty much over. Plone is more standards-compliant, according to my little unscientific benchmark.
Actually, this "benchmark" proves nothing.
Or does it? This quick test shows, at the least, that the Plone developers are more committed to standards than the Joomla! guys. It might be that the underlying technologies are strong enablers in this department (I truly believe this to be the case, having developed both in Python and in PHP). It might be that the Plone developers are more diligent. It might be a combination of both.