The company issued a FAQ along with the announcement, which explained that Criterion's stated intention was to acquire the physics assets, not the MathEngine company, which "...would have been a very complicated process."
Existing MathEngine customers will continue to be supported by MathEngine. Should this support not be available, these customers are advised to contact Criterion, "who [sic] will do what it can to assist on a case by case basis. Existing customers who have licensed physics through Criterion and new customers licensing from Criterion will continue to benefit from RenderWare's extensive 24/7-support operation."
According to Criterion, the acquisition of the MathEngine IP means that it can ramp up its plans to modify and extend the functionality of the physics middleware.