I don't know if anyone that works in these areas of Linux will see this, but here goes:
What would be really helpful to me is adding a few more ulimit commands to the shell. I'd love to be able to have control over the CPUs. I understand that this slightly crosses over into the area of the 'nice' command.
Here is a real world example: We run Firefox from a centralized server for our City employees. We also have a few cyber cafe terminals configured around the City, so that they can log into their personal email during breaks. I'd like to throttle those devices back so that their Firefox sessions only run on one CPU. If only one cyber cafe is in use, response would be fine. As more are used, they would only slow down each other..and not the rest of the City sessions.
Anything running once this setting was enabled would not even see the other CPUs and perceive that you are on a single CPU workstation. I can think of numerous places where this would really help me tune for machines that run hundreds of concurrent users.