Sorry,i was Hi when i wrote that. I have been told several times it can be difficult to follow what I write.
Ubutnu is ready for mainstream PC use and has been for at least two years now. I have been using Kubuntu, which is Ubuntu with the KDE desktop. Kubuntu is a Windows type user friendly Ubuntu OS, Windows 7 is quite similar in looks to Kubuntu. I like Kubuntu because it seems to have an ease of use for media programs. Many people already use Linux programs everyday such as VLC media player,Gimp photo editor,FireFox internet browser,Limewire,Bit torrent.cCleaner etc... With that in mind I don't think that it would be a hard to switch for most people.
The problem with all Linux,Unix operating system's, is their inability to fully run Games!!! This has little to do with the file system,driver's or binary code, it has everything to do with Money!! Games often take cutting edge Pc technology to it's limits. Most Linux programs are developed by volunteers or through grant's, or even by donation's from people like you! In other words, would you have given Crytek a donation if they had came out and said "we are looking to develop a cutting edge gaming platform for Pc's that takes an extremely cutting edge pc to run" I don't think so.
I use Kubuntu on an external hard drive. I have never worried about getting a virus with any Linux Os, since I close the code myself. I would not be concerned about catching a virus with Kubuntu or Ubuntu unless you are online logged in as the Root user. I have on occasion had to reinstall because of broken dependencies that i could not track down, but never from a virus. I backup quite often with a flash drive,only personal files not programs as Kubuntu takes little time to get back up and running. I could very easily be running this system on a Linux operating system for the next ten years, as apposed to the next 4 years with microsoft, and that is the the problem. There would be no reason to develop better technology if you just kept improving the Os to do more with the same equipment.
And lets face it we are all used to Windows