Recent studies have questioned the consistency and applicability of the existing implicit-solvent models in which solvent accessible surfaces (SAS) or solvent excluded surfaces (SES) are pre-defined, and used for the calculation of solvation free energies. As an emerging concept and theory, the variational implicit solvation determines equilibrium solute-solvent interfaces and solvation free energies by minimizing a mean-field free-energy functional. This free energy couples the surface energy, dispersive interaction, and electrostatic contribution. It can also incorporate molecular mechanical interactions. A level-set method is developed to numerically relax an initial interface of high free energy to an equilibrium in the direction of steepest descent. Numerical results demonstrate the initial success of the coupling of the level-set method with the variational theory of solvation, particularly in capturing the hydrophobic interaction. Such interactions are crucial to biomolecular structuring and dynamics, but are not well accounted for by SAS/SES implicit-solvent models. This is joint work with Li-Tien Cheng, Zhongming Wang, Yang Xie, Jianwei Che, Joachim Dzubiella, and J. Andrew McCammon.