The Samsung S8500 Wave was an impressive phone - the first SuperAMOLED. The original Wave was the first phones with Bluetooth 3.0 and Wi-Fi b/g/n. The Samsung S8530 Wave II has those too. It's also got the same 1GHz CPU, 5MP camera with LED flash and 720p video capture.
The Samsung S8530 Wave II brings Bada OS back to the high-end - a 3.7" screen WVGA screen, but Samsung made the switch to "Super Clear LCD". The Samsung S8530 Wave II runs the Bada OS v1.2, which adds a few small upgrades, including Over-the-Air updates support and a Swype-like text-input method [Source]