The Ubuntu team has pushed the next iteration of the increasingly-popular distro out. Version 7.04 of the distro, under the name "Feisty Fawn" (yes, I'm serious), is now available, both as Ubuntu and Kubuntu, which relies on KDE rather than Gnome. You can download it from the various Ubuntu mirrors now, or if you already have an install you can use the very handy system update utility. You may also want to browse the release notes. The installs all fit on a single CD, and releases for 32-bit or 64-bit processors are available.
There's an independent review of this release, that covers everything frm installation to configuration to software.