I'm not exactly sure what they are doing. Here is the announcement from their website:
As of November 10, 2008 DHL Express U.S. no longer accepts Domestic Express and Ground shipments, unless a valid DHL account number is used for payment.
The world's leading global express delivery and logistics company continues to deliver world-class international service. The recent changes to our U.S. network are designed to strengthen our ability to provide you with our industry-leading international services. And nobody has more experience shipping to more overseas destinations than we do.
Len Diamond
Ridgewood, New Jersey USA