Just a heads up, knife-hp is now available from Rubygems and GitHub.
knife-rackspace has been updated to 0.5.16 with a number of new features (https://github.com/opscode/knife-rackspace/blob/master/CHANGELOG.md). Support for the OpenStack-based V2 API will be added in the next major release.
Senior Technical Evangelist | Opscode Inc.
firstname.lastname@example.org | (512) 731-2218
Twitter, IRC, GitHub: mattray