This guy is filled with buzz-words, but how long has he been in the business?? Five Years? Obviously long enough only to see the Microsoft view of the world.
There are lot's of companies trying to implement AD, but the experience is that it is very painful and does not really scale very well, and by the way- AD is NOT fully LDAPv3 compliant. And keep in mind that even if AD was any good - which it is not - it is anathema for Microsoft to integrate well with anything open source - so the whole point of Linux is missed by them.
One other comment - Read Gartner, there are certainly strong competitors to AD and Sun i.e. Novell eDirectory - Look at CNN, Lufthansa, Star Alliance, Daimler-Chrysler etc. etc. They all use eDirectory. They must know something this turkey does not!