Sigurd Magnusson sent us an email to let us know that "SilverStripe has now split its company and open source projects into two totally revamped and beautiful websites".  The two SilverStripe websites will of course have different purposes.

Head on over to the SilverStripe.com
site if you want to know more about our company and the business side
of things. But if you're looking for the SilverStripe community,
developer documentation, or the roadmap for the future of the product,
you're in the right place [SilverStripe.org].

Explanation for the split was given at SilverStripe.org stating that the changes were made to "make navigation and discovery easier" for SilverStripe's customers and developers.  However, I suspect the purpose of splitting the site had to also do with the fact that SilverStripe as a commercial entity needed to have its business side become less visible in its own open source project. 

SilverStripe's decision to separate the commercial side and the open source side of their business is a strategic business decision.  I have observed that it is very difficult for open source projects to
flourish without a strong open source community supporting the
project.  Most open source communities become quite distracted when
commercial interests tries to circumvent control and direction away from the community.  By giving SilverStripe the open source community a chance to
flourish more on its own via a community website, SilverStripe the company
can spend more time focusing on the needs of their business customers
at SilverStripe.com.  Strategic moves such as this usually result in a win-win situation for both parties involved.