We often have our heads down looking at the projects we regularly work on (Apache CloudStack and Xen Project) and don't always pay attention to the other cool things going on in the open source world. So once and a while it's good to poke your head up olut of the clouds and take a look at some of the awesome projects being developed in the open source community. These projects are very promising and especially usefully for cloud comptuing.
Hybrid Cloud => Segregated Workloads
I am not convinced of the hybrid cloud scenario as espoused by many cloud pundits. I think it's more theoretical then the common place. What I do think happens is that organizations are using the public cloud and private cloud simultaneously with different applications in each and will continue to do so. That's why I like some of these tools that help users manage mutliple clouds (hopefully one of them will be Apache CloudStack ;) from a single tool.
One of my favorite projects is Scalr which gives users an easy-to-use menu-driven interface (See screenshot to the right) that enables them to deploy applications on multiple clouds. I have seen Scalr in use on a number of CloudStack clouds as well as being used to manage Amazon Web Services. Their template system makes cloud deployments a point-and-click proposition.