Terminal.com is writing next generation virtualization. This includes live-migration without hypervisors (already in production) and live-resizing (also in production).
I think we'd like to think we're working on the ugly bits of infrastructure people don't care about.
This includes a distributed file system optimized for speed and storing machine state like Github, software defined networking for IP migration across metal, and other abstractions for making devops easier.
We're looking for people who want to think about hard computer science problems like managing stateful systems more intelligently (think auto-failure detection and recovery and less I/O intensive WAN replication strategies).