Paul Thurrot, writer for Windows Magazine and the Windows IT Pro site has had a look at Ubuntu and honest as he is, he dares to say that he likes it!
In the small review, he acknowledges the slick interface of Gnome and mentions that:
Because Ubuntu is based on the well-regarded Debian Linux distribution, it uses that system's Advanced Packaging Tool (APT) software-update technology to keep the system up-to-date. And because it's Linux, the system is secure out of the box (well, there's no real box), requiring you to create a normal user account and supply the password to an admin-level account whenever you attempt to make a change to the system.
Ubuntu is a Linux distribution aimed at real human beings, and as such it's appropriate for just about any computer user. You might need a more technical person to help you set it up, but once you get up and running in Ubuntu, you'll feel right at home.