Isn't the Space Shuttle basically used to launch and recover satellites, and transport cargo and astronauts to and from the International Space Station? I'd bet we actually get more information and benefits from all the space probes that we've launched throughout the last few decades.
Well, most satellites are handled by independent launches these days (smaller rockets are just MUCH cheaper than sticking one into the shuttle to go up). Recovery simply doesn't happen. When they die, they either leave them or de-orbit them. Packing too much mass into the shuttle for reentry is just not seen as feasible or safe these days. Particularly after the loss of Challenger and then Columbia, they're just not willing to shift the mass very much.
You have to filter what this discussion has veered into into two separate topics: what good is THE SPACE SHUTTLE, and what good is manned space flight.
Most scientists hate the space shuttle. It's inefficient for one. The thing is HUGE, doesn't have a great safety record, costs a lot in fuel to launch, and requires as much prep time and resources in getting one ready for relaunch that you might as well build something new. A LOT of waste went into the simple political move of branding this thing reuseable. The Russians had a very similar project (the Buran
http://en.wikipedia.org/wiki/Shuttle_Buran) they they eventually abandoned out of practicality reasons. Another major problem is that the shuttle is a (largely) unchanging platform. Computer and mechanical systems have sat largely untouched since the original design. This makes finding replacement parts, and, arguably more importantly, engineers qualified to work on the shuttle, difficult to allocate.
All in all, a waste of money. Now, that aside, manned space flight itself is very good for research purposes. Loads of experiments have been conducted in zero gravity, and there's also the simple fact of exploration and moving out. If the Europeans hadn't decided to go exploring America would still be inhabited by Native Americans and few of us would be here. Not to mention that scientific research itself leads to all sorts of things. Chemistry and metallurgy research lead to our development of firearms. Bio-tech research has led to many of our medical treatments. Totally abandoning this type of thing is just not wise and WILL eventually lead to a stagnation in our technical progress - which in turn will lead to the fall of our society as others push forward. We'll be SOL if China and/or Russia get an orbital missile platform deployed and we're stuck trying to figure out a way to get back up there.
So, the answer here is what NASA is already looking at (though they should have done it long ago). Dump the shuttle. Go back to simple capsules atop a single rocket booster. Let it come back down and land via parachute (ocean or land - both can be done) rather than gliding in like a plane, and then toss the capsule. It's simpler, it's safer, and it's cheaper. There's also a LOT of work in the private industry that's been doing some interesting things on very small budgets (Space Ship One for example
http://en.wikipedia.org/wiki/Space_Ship_One). There is most certainly pork to be cut in NASA, but we should look at trimming the fat and making the system more efficient, and not dumping manned space flight altogether.