The supercomputing world is due to be turned on its head with the unveiling of the D-Wave quantum supercomputer that has massive computing power in one single chip. This will take the computing world in new directions. The ability to calculate many numbers simultaneously instead of one after the other will mean that you could crack passwords much faster than if you were using a traditional supercomputer cluster. A cluster of three D-Wave computers would have more computing power than an existing computer network that would take up an entire warehouse. This is the future of computing right now. Any encryption that exists right now could be rendered moot using this amazing technology. But a quantum computer can also be used to create quantum encryption that no existing computer could crack. That is the flip-side of having a quantum computer, you can keep your data safe from attackers using massive levels of encryption that others using standard CPU and GPU combinations would be unable to break. Would it be possible; with this technology, to build a quantum GPU for a gaming PC that could render real-time ray-traced photo-realistic gaming graphics? That would be incredible. Imagine playing a Crysis game with high-resolution textures that are just like real-life scenes for total immersion.
Especially with the Occulus Rift VR technology that is in development. We could be on the cusp of total virtual reality immersion, this is technology that has been featured in movies such as Gamer and of course in Star Trek with the holodeck that can project photo-realistic holograms of characters and a realistic solid world that the characters can interact with. This has been planned and could happen in the future sooner than we think: http://www.smartplanet.com/blog/report/a-real-life-8216holodeck-in-10-years-less-far-fetched-than-you-think/1081. Just imagine the possibilities if you could use a real holodeck to play a Doom or Quake game. There are also neural interfaces that are being developed by companies such as Emotiv that are intended to replace existing controls with a direct neural interface. See the website for more information: http://www.emotiv.com/. There is also an X-Prize that will be awarded to anyone that can create a medical tricorder as seen in Star Trek, this would revolutionise the world of medicine. A quantum computer would also do this, it would allow medical professionals to simulate various conditions to find a solution using the massive power of a quantum computer.
This is already done using supercomputers powered by the Nvidia Tesla GPU processors and Cray supercomputers: http://www.eweek.com/innovation/nvidia-gpu-cray-supercomputer-power-hiv-research-breakthrough/. But a super powered quantum computer would make this even easier, with the ability to simulate various viruses and bacteria in depth using the power of a quantum chip. There is a theory that our entire universe is simulated inside a massive quantum computer: http://www.technologyreview.com/view/429561/the-measurement-that-would-reveal-the-universe-as-a-computer-simulation/. There have been observations of fuzziness at the quantum level that does indicate that the entire universe is a massive hologram. It has been said that at the edge of the universe there would be a an area that contained all information about what is contained inside the universe. This is due to the fact that the entire universe is inside an event horizon and the edge of the event horizon contains information about everything that the universe contains. Does this mean that there are beings outside our universe that have created the entire universe as a simulation to test various theories and observe it as a science experiment? This could be what has happened.
That is an amazing thought, we could all be just test subjects inside a massive computer simulation; created by an unimaginably powerful computer. But this has yet to be absolutely proven to be a worthwhile hypothesis. But the benefits of quantum computing are many; even without a quantum computer, you can do amazing things on a GPU processing unit that you cannot do yet on a standard CPU. There is some information on quantum GPU Supercomputing, this is using a GPU as a processor for simulating various experiments.
Read about this here: http://opticalflow.wordpress.com/2009/02/15/quantum-gpu-supercomputing/.