There is a slide deck available here: http://buildacloud.org/blog/254-google-summer-of-code-2013-with-cloudstack.html
Apache Whirr and apache Provisionr are two projects that aim to do "one-click" Hadoop clusters on top of Clouds. They have limited support for CloudStack based clouds.
This project will be about making sure that Whirr and Provisionr can make use of CloudStack to deploy Hadoop clusters. You will need to understand how to do configuration management and deploy all the required VMs for a hadoop cluster. In addition the project can look at how to implement a similar functionality to the AWS Elastic Map Reduce.
Write a proposal and submit your applications to the Google Summer of Code.
Register on the Cloudstack mailing list if you are interested: email@example.com