Please don't confuse GPU computations with CPU. Although a GPU can have thousands of individual processors, they are much slower than a CPU for the equivalent calculation, and have to be supervised, which results in considerable overhead. (Amdahl's Law), and suffer other limitations.

The basic rules of computation still apply.

In any case, most cracking records are set in circumstances that offer opportunites that seldom exist in reality, where delays are the norm and lock outs for incorrect passwords are applied.

Plus, how likely is it that some criminal mastermind is going to use the entire resources of his zombie computer army for several years to get his hands on your copy of V4?

I think BB's vision is very welcome. Just think of well maintained freeware libraries that we could automatically sign up to and access from anywhere. Bring it on!