I don't like small screens for watching video. I wouldn't watch video on a laptop or a netbook or an iPad or an iPod/phone or a PS3 portable or any such small device given the choice. I might do so while on a trip and if I did, I would want to bring along my own videos, not pay to stream them from Apple. And Apple won't have any porn anyways. lol
It doesn't take much to prevent a virus from infecting Win 7. The free antivirus program, Microsoft Security Essentials, is more than sufficient for the average user and a 10 year old could install it. All it takes to keep malware, there are next to no true viruses these days, off your computer is a bit of common sense. In other words don't click on popups that say 'click me' or open email attachments that you aren't expecting. This is the same as it has always been. And even if you do click on something in IE8 running in protected mode as it is by default, it would still require user permission to install itself on your system.
Basically...if you get malware on a Win 7 system, you have installed it yourself. Similar to what it would take to infect a Mac.
As far as ease of use..if someone can't figure out Win 7 in a number of minutes, they have no business anywhere near a computer and should buy an iPad instead.
And new or not, many netbooks are still being sold with XP, unfortunately.