For more half-baked ideas, see my ideas tag
When manufacturers build consumer hardware it is often subjected to so-called “accelerated aging” or “accelerated testing”. For example, the life of an aircraft is not measured in years, but in pressurization cycles. Aircraft are repeatedly pressurized in tanks, and shaken (“fatigue testing”) to find out when they will fail.
So here’s the idea: Apply accelerated testing to virtual machines. Modify pvclock so it runs 100 or 1000 times faster than normal. Daily and weekly cron jobs accelerated, and so are daemons, so we rapidly find if they slowly leak memory or disk space, or have some other time-related failure. How will the guest behave after it has been running for a year, or 10 years? How about applications? Now we can find out, and not need to wait that long.