The Sony RX10 and FZ1000 are both a new breed of hybrid/bridge cameras with large, one-inch sensors and fast, super-telephoto zoom lenses. Panasonic introduced the FZ1000 for just $899 and offers most of the features of the RX10. It also one-ups the RX10 by offering 4K video recording.
It makes sense then that Sony drops the RX10 price in order to stay competitive with the new FZ100. You can find the reduced Sony Cyber-shot RX10 here at B&H Photo.