NASA has already promised its space shuttle fleet to museums after their last launch later this year. Instead, a private company has made a proposal to buy up two of the shuttles and keep them flying commercially.
Most of the people involved in the space shuttle program aren't actually working for NASA. Instead, they're contractors, working for a company called United Space Alliance, which is a partnership between Boeing and Lockheed Martin. USA has thousands employees, and they're the people who do all of the processing and operational work on the space shuttle fleet.
Instead of just packing up the generally reliable and still fully operational shuttle program and firing the vast majority of the people involved, USA is asking NASA to let it take things over and launch Atlantis and Endeavour twice a year carrying commercial cargo starting in 2013. It would be called the Commercial Shuttle Transportation Service, and it would cost only about $1.5 billion a year, some of which would hopefully be offset by the amount of cargo that could be carried on each launch. Plus, there'd likely be room for a couple extra passengers, too.
Part of the reason why this might make sense is that keeping a shuttle or two operational would ensure that the US has operational manned heavy lifting capability to the International Space Station until we can get our next launch system figured out, whether it's a NASA project or, more likely, a commercial system. Retiring the shuttles as planned would leave a gap of several years at the minimum where we'd have to rely on the Russians, and while there's nothing wrong with that, it's always good to have redundancy when you've got a bunch of people up there in a space station with no parachutes.
United Space Alliance recognizes that their its is "very much a long-shot," which it definitely is, and NASA isn't commenting on the concept. Personally I'd love to see the shuttles continue to fly, especially if it means a potentially cheaper civilian ticket to space.