I've been MS free for over a decade and my parents and brothers for about 3 years. Debian and then Ubuntu.
Had this page included some illustrative video about what comes preinstalled with each system in a little walkthrough this A or B page may have been more fair. They could also include a primer to cloud services. I think grannies might consider Ubuntu if they saw how well it suits their needs.
I think the "new user" point makes sense coming from Dell. They sell software and would like to offer consumers the gratification of buying something that will work on their new computer. I think this works both ways. The consumer wants to buy Office, an awesome CPU-munching anti-spyware app (who doesn't), and a handful of games.
Dell customers who take Ubuntu home will be left holding their discs in their hands. I remember (and worked) at CompUSA when it was possible to buy CorelOffice and Loki games off the shelf. Those days have passed and with todays generation of console, Flash, mobile, and HTML based games ... and OpenOffice, who needs them. People would happily keep their $100-$500 Office dollars if they knew about Google Apps.
I still have the worst luck picking mid-consumer grade printers off the shelf that work under Linux without hitting the net first. I thought all Brothers were safe and I bought my mom the one that wasn't - now it is a coaster.
I think any programmer - not just "open source" programmers would benefit from the Ubuntu choice. Did they really have to spotlight the Games menu?