"Big Data" is a much-hyped term nowadays in Business Computing. However, the core concept of collaborative environments conducting experiments over large shared data repositories has existed for decades. In this talk, I will outline how recent advances in Cloud Computing, Big Data processing frameworks, and agile application development platforms enable Data Intensive Cloud Applications. I will provide a brief history of efforts in building scalable & adaptive run-time environments, and the role these runtime systems will play in new Cloud Applications. I will present a vision for cloud platforms for science, where data-intensive frameworks such as Apache Hadoop will play a key role.