The Population Clock accidental and intentional solutions

I expect to see over the next decade a trend towards techniques such as the Infertility virus

The fear is of course that such a virus might jump species - that may or may not be a danger depending on how it acts

Dr Lyn Hinds: People are very concerned when you talk about using genetically modified organisms. This is a virus and people don't always understand what viruses can do. We hear about viruses perhaps jumping species. This mouse virus, we're running tests now to ensure that it is truly only going to infect mice.

But an interesting question is if it did happen - would that be a good or a bad thing if we accept that the earth is already over populated and it shows little indication of stopping growing until it is well past 20 billion.

Of course committing genocide on the human race is not the plan here it is instead to have a way to bring down the population while causing the minimum amount of suffering. And it seems highly unlikely it would cause us to become extinct because

1) The virus will almost certainly not be able to cause all people to be infertile.
2) You will always be able to use antiviral treatments and artificial insemination.

Scary?
What if a smart scientist in a small lab with some good contacts followed the same logic outlined here and thought he would do the world a favour?