For details please refer to the newsgroup in question itself (which is a advicable place to visit anyway for anybody interested in the Robotics Studio).
As to Studio services not running on the NXT hardware
[...] in the case of the NXT, if you want to create an application with our development tools you do require a PC with the NXT and [...] we do not currently support code development and deployment on the NXT hardware. This is the approach that we discussed with LEGO and they agreed would be the best way to start.(tandyt,06/29/2006)
[...] rather than assuming that all your processsing horsepower is limited to a single compute unit, it can be spread across multiple processors. [...]I believe that our future will not be of isolated robots doing multiple functions, but sets of specialized robots that are coordinated (or maybe both).(tandyt,06/29/2006)
What would be required is to port our runtime (probably subset) to run on the native firmware (or replace the firmware with something like Windows CE).(tandyt,06/29/2006)
[...] this could probably be done by a third party, but probably requires
some technical information/support from LEGO and Microsoft. Generally we
would expect a hardware vendor to provide this with support from us [...]
We need to talk further with the folks at LEGO because creating something that would natively compile and execute would compete with what they are supplying.
Features planned for upcoming releases
[...] we are working on a program to run on the NXT which will properly inform our services of sensor events.(Ben Axelrod, 06/27/2006)
We can also give you a nice debugging environment for your custom code that you can download on the NXT, plus a UI to monitor your NXT when its roaming(George Chrysanthakopoulos, 07/03/2006)
Bluetooth communication from NXT to PC] is definately possible and its exactly we will be showing with our next set of LegoNXT services and tutorial.(Ben Axelrod, 06/27/2006)
[...] we do plan in our next release to give you a lot more "standalone code" that runs on the NXT and communicates with MSRS services on the PC.(George Chrysanthakopoulos, 07/03/2006)
Pricing model (will Robotics Studio be available for free in the future also?)
[...] we haven't announced final licensing yet. The preview is free for all to use. Like our VS folks we prefer to evaluate the response to the preview before we lock things down. Further, we do understand the state of the industry and the community(tandyt,06/29/2006)
and believe that at the present time it is not likely to generate large
revenues yet and to help the industry bootstrap itself it must be affordable
to a large audience. So we are evaluating how best to do that which still
makes good business sense and while I won't make a commitment at this point,
the model our VS people have adopted about having a free subset and a
moderately priced commerial offering is attractive.