I know that OS X is in the process of coming out with something similar in a little less than a year. This is certainly a step in the right direction for them. However, you won't be able to see your workspaces without a zooming expose-like step that, despite its original sexiness, can become annoying really fast and negate the time saving benefit of the workspaces.

4.Stability

Granted this is something OS X does quite well also. However, in my experience Linux is even a little bit more stable than OS X (and WAY more stable than Microsoft Windows). This seems to be largely due to the openness of much of the code used in Linux. Because the code is so accessible it has allowed an amazing amount of people to proof-read it and spot those annoying little bugs that lead to crashes.

5.Security

There are firewall and anti-virus programs for the Linux system that are freely available and installable with a single click. These are truly industrial strength programs, and the ones that are used on many many of the computers that house websites. Yet, for the most part these programs are not needed by a desktop user. The system was designed with security in mind. For example a malicious program can't do anything to almost all of the important system files on your computer without your system password. By simply refusing to supply that password to suspect programs a great many problems are avoided. This permission based system can also prevent one from messing up their own computer by mistake (and prevent guests from changing your system settings when you are not looking).