VMware are currently running a promotion around the exams for the VCAP4-DCA and VCAP4-DCD certifications - a 50% discount voucher to anyone who attends one of the recommended training courses.
It's not compulsory to attend any training courses to take a VCAP4 exam, you do have to be VCP4-certified (which does have training requirements) but you can then self-study in terms of preparation for the VCAP4 exams.
There are recommended courses for each of the two certifications, and if you review the exam blueprint documents for either of the certifications (VCAP4-DCA blueprint, VCAP4-DCD blueprint) you will see the strength of the relationship between these courses and the exams:
vSphere: Manage for Performance
vSphere: Automation with PowerCLI
vSphere: Manage and Design for Security
vSphere: Design Workshop
Attend any of the above instructor-led courses between now and November 30th and the week after your course VMware will email you the 50% discount voucher. For further information, follow the link to the VMware Education Services page and click the Learn More icon under VMware Training and Advanced Certification - here's the direct link too.