There's a new Ubuntu Cloud Infrastructure project that recently took another big step with the release of Ubuntu 11.10 Oneiric Ocelot.  This project replaces the old Ubuntu Enterprise Cloud and ships with 11.10.  It's also based on OpenStack for quick, cross-compatible cloud deployment.  The Ubuntu Cloud blog also gives us 4 steps to deploying UCI on a large scale with DevOps-style automated infrastructure tools including Orchestra and Juju:

Currently if you’re a developer or tester who wants to “play” with that product, your best bet is to grab the Ubuntu Cloud Live USB stick image here. Boot that on any AMD64 box and start launching cloud instances.

However if you’re looking to deploy Ubuntu Cloud Infrastructure on a larger scale, the Ubuntu server team has your back! Here’s what needs to be done:

• You will need enough hardware boxes for a scalable deployment (at least six boxes, or fewer with certain tricks to collocate services on the bootstrap node)
• You will need to setup an Orchestra automatic network installation system. This is documented in my previous article about deploying server fleets (part1, part2)
• Afterwards, you will need to setup juju to “control” the Orchestra machines. This is documented here
• The final step is to checkout the Ubuntu Cloud juju charms, and start deploying components. Needed docs are here!
  
  
  -The Ubuntu Cloud Blog

The automated hardware deployment tool, Orchestra, and service deployment tool, the Juju framework, are available to you today for free.

Source:  http://cloud.ubuntu.com/2011/10/ubuntu-cloud-deployment-with-orchestra-and-juju/