How many 4GHz chips have been produced that don't need watercooling to operate at load?
Pretty much every intel desktop chip of the last few years will do 4ghz+ with good air cooling. I have an i7 930 @ 4.2ghz on air, my flatmate has a 2600K @ 4.8ghz on air.
Lots of things can run faster than they are supposed to, but that doesn't mean they should or that people are going to like the solution. Often times the bleeding edge processors are clocked according to MTTF based on a reference implementation (which would include some standard of heat dissipation and a processor's TDP and probably not exotic copper heatsinks and high speed fans. If this fan can more efficiently transfer heat out of the processor and dissipate it with a lower total energy consumption, then it could be very useful, especially when you are talking about things like datacenters where total energy consumption and MTTF are things that really matter.
If you can improve the MTTF by leveraging this technology to make the entire server highly resistant to dust fouling, then there might be another tremendous benefit for datacenters.
The real issue is the power consumption, not the actual heating at 4GHz. But even if we don't count the OC, 3.1GHz+ is still beyond 3GHz by any decent math.