It takes more than moving an enterprise software application to an internet data center to make it a cloud based computing application.
Yes, you can make it work on new virtual server technology, new virtual storage, and improve the reliability and performance, but that doesn’t make it a cloud application.
Yes, you can replicate the data to multiple sites and eliminate the risks associated with regional disasters, but that doesn’t make it a cloud application.
In order to make it a cloud application you have to take advantage of new concepts.
Think of putting your data in a cloud that doesn’t need to be tied to a single application but supports many applications.
Think how to make that database massively parallel so that it supports writes and reads for billions of users.
Think how to make the database maintenance non-disruptive.
Think how to backup this data.
Think how your application will be only one of the applications supporting this cloud architecture.