As the cloud has been now popularize, whether it is private and public cloud we need to have some ways qualify these people just like for desktop VCP5-DT.
Requirement will be the same as desktop, you would need to be a VCP5 first. You can check out Eric Sloof's post.
Sign up for to be informed once VCP5-IaaS goes GA here.
For more information on all the certification you can refer to certification site.
Update 31th May 2013
VCP-IaaS exam is now certified as VCP-Cloud.
There is some confusion so here I share explain as below.
If you are a VCP5-DV, you would need to just take VCP-IaaS which contain 85 questions to be VCP-Cloud. This exam will require per-authorization and a check if you are VCP5-DV will be done before granting you to even see this exam to be booked.
What if you are not VCP5-DV but a VCP4-DV? You can also be VCP-Cloud. What you need to do is attend one of any of the two vCloud courses and take the VCP-Cloud. The number of questions in this exam will contain 135 questions as it covers some vSPhere 5 questions as well. However this does not give you VCP5-DV. You can refer to the certification page for VCP-Cloud here.