The NSZ-GU1 has an IR blaster like other Google TV boxes, and Bluetooth where the Chromecast doesn’t include either. The power adapter it’s tested with also could be overkill for a simple dongle-like device
Despite some speculation that it could be a Chromecast stick, it seems unlikely.
Google SVP Sundar Pichai recently told AllThingsD that Google TV “will be a full-fledged Android for television,” and that the company will be announcing more manufacturing partners at CES next year. One of those projects is believed to be an Android-powered set-top box with a motion sensor similar to Microsoft’s Kinect.