MICGadget have published this hands-on video of the ZTE Tania, which will also be known as the ZTE Spirit.
The device is not too poorly styled, but looks thicker than it really is. At 10.5 mm it is actually thinner than the HTC HD7 (11.2mm) but I would not exactly call that ultra-thin these days.
The specs sheet unfortunately makes it clear that the 4 GB of storage is no typo, and another picture shows only 1.21 GB free, but the the picture with the back off suggests there may be a slot hiding there somewhere.
See and read more at PCHome (chinese).