ubuntu-10.04-beta1-desktop-i386.iso (675MB, torrent),
ubuntu-10.04-beta1-desktop-amd64.iso (679MB, torrent).
Also release today were 10.04 beta 1 builds of Kubuntu (download, release notes), Xubuntu (download), Edubuntu (download), Mythbuntu (download, release announcement) and Ubuntu Studio (download).
Reference to Announcement is h3r3
Quoted from the Announcement and some features :
Server features --------------- Cloud computing: The Ubuntu Enterprise Cloud installer has been vastly improved in order to support alternative installation topologies. UEC components are now automatically discovered and registered, even with complex topologies. Finally, UEC is now powered by Eucalyptus 1.6.2 codebase. UEC and EC2: Ubuntu 10.04 LTS continues the tradition of official Ubuntu Server image releases for UEC and for Amazon's EC2, giving you everything you need for rapid deployment of Ubuntu instances in a cloud computing environment. UEC images, and information on running Ubuntu 10.04 on EC2, are available at: http://uec-images.ubuntu.com/releases/10.04/beta1 Stability and security: Ubuntu 10.04 LTS brings many improvements over Ubuntu 8.04 LTS to keep your servers safe and secure for the next five years, including AppArmor profiles for many key services, kernel hardening, and an easy-to-configure firewall."