The VCP on vSphere4 (VCP4) certification exam will be publically available on August 8th, 2009. It is already possible to schedule an appointment at Pearson vue.
In about a week, on July 6th, 2009, the beta exam for VCP on vSphere4 starts and is only eligible for people who participated in the private beta program on vSphere, the candidates will be contacted by VMware.