No, and in fact we need all these efforts.
OpenStack and Apache Deltacloud do have similar goals. They're both building out lightweight REST APIs so companies can tap into the services of a cloud provider over an HTTP network. But they're likely to be used for different purposes.
Rackspace OpenStack backers are looking to provide systems that can be used by cloud services suppliers, who might manage up to a million servers. Even though it will be aimed at service providers, if OpenStack is widely used, customers would be able to deal with providers the same way.
Red Hat's effort will be more likely be used by enterprise customers, giving them a software stack based on open source code with which to build private clouds around Red Hat. It will also make it easier for cloud service providers to interact with that private cloud, if they support Red Hat's approach.
RightScale CTO Thorsten von Eicken calls OpenStack a "true open source project," with vendor participants and a community around the resulting code. That may sound a bit defensive about the group's open source cred; after all, it's led by vendors, each with a commercial interest. The Deltacloud project, now in the Apache incubator, is a more classic open source project, open to developers around the world who will dilute the commercial interest of any one company.
But I don't care about the hair-splitting. We need all three of these API efforts to evolve the cloud, so it connects to many different customers and implements varied styles of computing. We are at least headed that way.