La NASA ha inviato un report sul futuro della ISS al Congresso in cui spiega le linee guida dei piani futuri che intende seguire nella gestione della stessa.
Alcune analisi da nasaspaceflight.com
Briefly, as stated in the Vision for Space Exploration (VSE), it was to complete the assembly in a way that meets our international commitments, rescope the onboard and ground-based research towards studies needed to support long-duration spaceflight and the needs for exploration - oh, and grudgingly comply with the congressional mandate that 15 percent of the station research be non-exploration-related (a measly $17 million/year, on average) - and plan for continued operations on that basis through its previously-expected life-cycle, ending in 2016. That is pretty much about all there is and has been since January 14, 2004.
As for gaining access to it, once completed, the answer was (and still is) to purchase Soyuz and Progress services from the Russians (only currently a legal option through 2011, due to the constraints of the Iran Nonproliferation Act), hope for the success of the Commercial Orbital Transportation System (COTS) program to help develop a US-based commercial service option, and yes, as a side-bar we’ll design the Ares/Orion exploration vehicles so that they ‘could’ also make runs to and from ISS (though no sooner than 2013 in the very best current scenario).
Statement of the possibility of using heretofore 'demanifested' hardware and facilities - again assuming transportation can be made available - to be launched to ISS and put to use.
Depending on the transportation systems and resources to become available, this could mean such experiments currently in ‘limbo’ as the Alpha Magnetic Spectrometer (AMS), the Centrifuge Accommodation Module (CAM), or the X-Ray-based autonomonous Navigation (XNAV) experiment could find renewed possibilities for deployment - and preserving billions of dollars in otherwise ‘wasted’ investment if they were to left on the ground.