I just stumbled across the following on the mindsensors.com products:

EV3 Sensor Adapter for NXT or Arduino

Using this adapter, you can attach new EV3 sensors to your NXT or Arduino.
(This is basically a UART to I2C adapter).

• For NXT, works with BricxCC, and new EV3 IDE for NXT
• Lightweight and small design, that fits in-line with your sensor and brick
• Use with Arduino with NXShield

I will test this adapter in the near future and write more about it here. Because the adapter is not supporting NXT-G, but the new EV3 IDE together with the NXT brick, this will then also be my first time using the new software with the „old“ NXT hardware.