Mining cancer data in the cloud is great, but to enable ongoing research there should be a connection to specimens so researchers can pursue followup studies. This will require storing data about specimens from studies such as TCGA - where they are, how they can be accessed and what consent they are governed by.
Just as the data from publications should be made available to allow reproduction of results, so should samples be made available. Acquiring samples is a time-consuming and costly process. Anything we as a community can do to re-use such resources should be encouraged.