Silent HIPS of the future!

The problem with silent HIPS is that there is no effective way as such to test it's effectiveness as you have no idea what it might have missed altogether.

Besides more powerful AI in these products is what is required, but as some others have already said the problem is simply that tracking hostile behavior based solely on lists that the AI uses as entry variables to make decisions is not without it's pitfalls either...

Personally I don't think that a fully silent HIPS is actually possible as for it to be effective a process by process assessment is required and due to the dynamic nature of executables it is actually impossible to be exact as to the nature of said process and as such user intelligence is required to be effective...