The GT3 RS is wearing the new GT3's revised face. It's similar to the current model, with intakes and vents in almost the same positions, just slightly shifted and smoothed out. It's more evolution than full overhaul. There are some taped-over vents on the frunk, though it's not clear what their purpose may be. While the headlights have been updated, the fenders look like they're the same ones that are on the current car. In fact, it doesn't look like there have been any exterior changes past the A pillars. Same wheels, same wing, same exhaust.
Expect some major changes underneath, especially to the engine and transmission. At 500 naturally-aspirated horsepower, the standard GT3 has the same output as the outgoing RS model. The new GT3 RS should make somewhere between 520 and 540 horsepower from a flat-six engine. Even better, look for a manual transmission to complement the current car's PDK offering. Fast as it may be, a dual-clutch transmission is no substitute for a good old-fashioned manual.