Duel booting Ubuntu and Windows is very useful and important...
@"dual-boot environments, which Shuttleworth called a new frontier for Canonical."
It maybe new to him, but I've been duel booting Ubuntu and Windows for a few years. (My previous PC was triple bootable as it was Win98, WinXP and Ubuntu), so its been possible (and very usable) for years. I think its a very good way to encourage more people to get into using Linux, if all they have experienced so far is Windows. :)
Getting people over this initial learning curve I think is very important. Once they have experienced Ubuntu/Linux for a while, it helps to overcome a lot of their fears about it. So by allowing them to use it whilst still clinging to their old Windows copy as well, it helps convince a lot of casual web users, Ubuntu is all they need to do all they want, (e.g. web, emails, documents, photos, etc..).
For more technical users, like I guess a lot of people on here, my company still requires me to work in Windows a lot of the time, so its very useful to have a duel booting machine.
@"Canonical also unveiled Ubuntu Light, which is based on Unity. It features chat, IM, a browser, and a media player."
Also don't forget Ubuntu Studio, which looks very tempting to a lot of users, as it comes with many media tools pre-installed (Audio, Video, Graphics) and for anyone new to Linux its mind blowing for them to tell them they can get all this for free. That really helps shock people into changing their perception of Windows. :)
Here's the link: http://ubuntustudio.org/
This gives a good overview of all the tools you get with it.
The more Linux users the better. :)