If there is a single complaint that is laid at the feet of Linux time and time again, it's that the operating system is too complicated and arcane for casual computer users to tolerate. You can't ask newbies to install device drivers or recompile the kernel, naysayers argue.
Of course, many of those criticisms date back to the bad old days, but Ubuntu, the user-friendly distribution sponsored by Mark Shuttleworth's Canonical, has made a mission out of dispelling such complaints entirely.
Hardy is what is known as an LTS (long-term support) release, meaning that patches and paid support will be available for at least three years after the release. Canonical has been dropping new releases about twice a year, ensuring that the kernel and software packages stay fresh. There are a lot of neat new features in Hardy, but let's start by talking about what makes Ubuntu such a great distribution to begin with.
Ubuntu is based on Debian, which enjoys wide developer support. Having a vibrant distribution such as Debian as Ubuntu's underpinning has resulted in a very stable and feature-rich distribution. Raw Debian has a reputation as being a bit geek-centric, and although it makes a good effort to be easy to use, it still can be a challenge to install for nontechnical users. Ubuntu has put padding on a lot of Debian's sharp corners, without removing any of the power of the underlying distribution.
One of the killer features of Ubuntu is that the installation media is also a "live CD." This means that you can boot it off the CD and try it out first before installing it. (You can also set Ubuntu up to boot off a USB drive.) In other words, you can make sure that all your hardware will work correctly and that you're happy with the look and feel of the operating system before committing yourself to anything permanent. You can also carry it around and use it to boot up a friend's computer under Ubuntu.
And when you do install it, you'll be asked a minimum of questions, and none of them are in the least challenging to anyone who has ever installed Windows. The install is even smart enough to help you resize an existing Windows partition (even Vista!) to set up a dual-boot system and set the boot menu to handle it.
Ubuntu has also taken a flexible attitude toward proprietary drivers. Some distributions, philosophically opposed to letting companies "poison" the intellectually free Linux landscape, pretend these drivers don't exist. This can lead to poorly performing hardware or, in some cases, unusable Wi-Fi connections or audio hardware.