This article is just a bunch of smoke. Ok, we know Apple doesn't use Adobe's DRM for eBooks in Apple's store. And why should they? Why pay out licensing fees to Adobe who has nothing to do with Apple's investment in creating the iPad or running the iTunes store? Would any of you suddenly be willing to share part of your paycheck with a complete stranger every week? Apple has a perfectly good DRM system already developed in-house that worked just fine protecting music and still protects video content. Faulting Apple for not adopting Adobe's system for any reason is just plain silly, remember first and foremost Apple is a company and like all companies it is out to make a profit for itself, not give it away freely to anyone else.
The second major point, is no one has said that Apple won't allow someone else to create an application that will allow you to browse and buy eBooks from someone else's store that might use a different DRM scheme. Infact evidence (Kobo Books)
already points to 3rd party reader applications on the iPad and as we know there is an iPhone version of the Kindle reader. Apple pulling the plug on it running on the iPad would create a huge amount of negative press and feeling and certainly put a larger chill on sales than what they stand to lose on just the eBook market. Remember the iPad is for more than just eBook reading and Apple makes a hefty chunk selling music, video and application content.
In any case, the iPad isn't released to the public yet and the Apple Book store isn't open yet, so until these conditions change articles like this don't do much more than spread FUD (and quite successfully to, just look at the various threads on here).