The third alpha release pulls in the latest Linux 2.6.38 kernel development code, Upstart 0.9, a dpkg 1.16 preview, rebuilds all main packages against Python 2.7, and simplifies the Ubuntu desktop installation. Other features of Ubuntu 11.04 include improvements to the Ubuntu Software Center, better Ubuntu One integration, the Ubuntu ARM Netbook edition sporting the new Unity 2D interface, and the most dramatic change is the new Unity interface to the Ubuntu 11.04 desktop. There are also improvements to Ubuntu Server, Kubuntu, and Xubuntu.
Details and download links for Ubuntu 11.04 Alpha 3 are available here. Up next is the Ubuntu 11.04 Beta at the end of March and then the final release of Ubuntu 11.04 is planned for 28th of April.