Well-known virtualization blogger Kendrick Coleman has published a version of the VCAP4-DCA exam blueprint in the form of a set of links to the key technologies and documents covered in the exam. It's the most comprehensive VCAP4-DCA guide I've seen so far, couple it with my recent blog post of beta exam review links and you've got an excellent set of resources.
Here' the link to Kendrick's VCAP4-DCA page:
Simon Long did the same thing a while back for the VCP4 exam, and has been updating the links on his page to point to the documentation for vSphere 4.1. Simon has also started working on a VCAP4-DCA page similar to Kendrick's, the links will follow once Simon has caught his breath from starting a new job at VMware...
Here's the link for Simon's VCP and VCAP4-DCA pages: