While there are many differences, some of the key changes would include:
The foreign language component has been changed from a general education requirement in USP to a proficiency-based requirement that must be completed prior to graduation
USP required more than 40 credit hours to satisfy, whereas UK Core requires 30 credit hours (or equivalency)
There is no math ACT/SAT opt-out for the Quantitative Foundations requirement in UK Core
More information can be obtained by viewing the Office of the Registrar's University Bulletin pages for each program - University Studies Program (USP) or UK Core.