Cloud computing alone is a very vast topic and here there are lot of things you can proceed for your research work.
There are still many utilities not familiar to people.
anyways there are few topics I found you can proceed with
-
Green Cloud Computing
-
Cloud Security
-
Cloud Service Model
-
Cloud Deployment Model
-
Mobile Cloud Computing
-
Cloud Cryptography
-
Load Balancing
-
Virtualization
-
Cloud Analytics
-
Cloud Scalability