There is no standard definition to this term. It is not defined in any recognized project management reference.
However, from what I've read so far, cloud computing project management means one of the following:
- Using a project management tool in the cloud (meaning that there are multiple servers hosting the tool)
- Managing a cloud computing project - such as devising/installing a "cloud" system for a specific company.
In any case, I think as the below answer states that cloud computing is mainly a useless buzzwords promoted by the creators of online PM tools.