Docker

I'd highly recommend checking out docker as the next cool tech to get your geek on. Vagrant and Boot2Docker are two options if you're not on Linux.

During a talk I gave recently, the topic of whether containers could talk across different hosts came up during Q&A and I mentioned this really cool project which basically enables distributed computing leveraging docker:

http://www.serfdom.io/

also check out coreos:
https://coreos.com/ 

mobile virtualization will likely be coming along in the near future considering the fast pace of innovation:
http://www.forbes.com/sites/tomkemp/2013/02/25/when-virtualization-meets-mobile/

All kinds of action happening in the management/orchestration space above docker:

http://mesos.apache.org/

https://github.com/GoogleCloudPlatform/kubernetes

Check out this little useful nugget someone put up for building Cyanogen via a docker container. A heckuva lot simpler than manually setting up all the prerequisites!