It seems that this new engine is presented is "the third major iteration
of [Havok] physics technology since the company was founded 15 years ago".
Second iteration, far-famed Havok 2.0
was a result of integration between Havok's own technology and third-party Ipion
physics engine, which was aquired by Havok in 2000.
Many Havok Engine releases has passed since then (around 8-9), so it is going to be interesting to see what they will offer this time.
We have seen dramatic performance gains with simulations running twice as fast or more, and using up to 10 times less memory. Additionally the new core's performance is extremely predictable, eliminating performance spikes