to the details over at Techreport.com, Nvidia is going to have five mobile GPUs in its 9 series. The confusion starts when you take a look at the specifications of 9800M GT and 9800M GTS.
According to the specification list, 9800M GT has more stream processors than the 9800M GTS, 96 over 64 stream processors. The confusion starts when you come to 9800M GT which, at least according to the naming scheme that we could see in the past, should sit below the 9800M GTS. Unfortunately for consumers, Nvidia apparently likes to confuse people so that the 9800M GT will end up quite faster than the 9800M GTS, since it has more stream processors and gives a higher number of GigaFLOPS.
When you compare these to the desktop versions, we can see that the top of the line 9800M GTX is similar to the Geforce 8800GT. They both have 112 stream processors and a 256-bit memory interface. The 9800M GTS is also similar to the desktop version of the 9600GT card, it has the same number of stream processors, but it also has a lower memory bandwidth. According to the specification list, the entire mobile 9-series lineup has the same 256-bit memory interface.
This is how the list of specs looks now and you can find more details over at Techreport.com