New UE Viewer version has support for StaticMesh from Unreal Engine 4. There's not serious games made with this engine yet, so I was able to test it only with WARMACHINE: Tactics and stock Unreal Engine 4.5. Materials support is not implemented yet, however some materials are correctly displayed (all meshes from WARMACHINE: Tactics are displayed textured).

Attention: only those models could be viewed which are located inside cooked packages (uasset files). Non-cooked packages doesn't contain geometry data - they contains a source model (fbx) and a link to geometry data from DerivedDataCache.