Is the Samsung SGH-I957 the successor to the Galaxy Tab 10.1 tablet? What we do know is that a device with this name has just been listed on the Bluetooth SIG website and is being described as a "Mobile Tablet".
It shares the same format (SGH-I9xx) with Verizon's Samsung Galaxy Tab 10.1 (SGH-I905). A quick look at their Bluetooth profile shows that the SGH-I957 has two additional fields; the "headset profile" and the "Personal Area Networking Profile".
The rest is exactly the same except for the fact that the Galaxy Tab 10.1 comes with Bluetooth 2.1 while the latter iteration has the newer Bluetooth 3.0 configuration; The SGH-I957 hasn't passed Wi-Fi certification yet and isn't currently registering on Google.
From there, we can only speculate on a few things, assuming that Samsung does indeed have a new tablet in the pipeline. Firstly, the fact that it has already been listed on the Bluetooth SIG means that it is near to delivery. Secondly, it is not the 3G version of the Samsung Galaxy Tab 10.1 because the Bluetooth Specification name is different. Lastly, the hardware version number for the SGH-I957 is v1.0 which means that it is a new model altogether (in comparison, the SGH-I905 is listed as v2).