NASA is currently developing a telescope to further probe the final frontier, and this new telescope, called the Webb telescope (after NASA's second administrator James Webb) or JWST, is being launched in many ways to replace the Hubble. It is designed to capture and analyze infrared light and has a primary mirror at least two and a half times larger than the original Hubble, and it is hoped that the Webb will be able to see deep into dust clouds and observe the formation of stars, planets and relay pictures of some of the universes' earliest stars. The possibilities presented are enormous, and unfortunately, the costs have been too. Regardless, Webb is scheduled to be launched sometime in 2014 and promises to be Hubble's finest successor to date. On the telescope's website are some nifty graphic tools that help contrast the Hubble and the Webb.
The telescope will be orbiting one of only five "Lagrange" points, nearby our planet, which effectively allow 3 masses (the sun, the earth and the Webb are the gravitational forces in question) to orbit each other while staying in the same places, relative to each other. The advantages this gives the telescope are many, including more efficient communication.
On top of it all, the Webb looks just like a Star Destroyer. How cool is that?
The Webb is still in testing phase, and much of it has yet to be built, such as the large lower structure, which serves to shield the apparatus from eventually harmful rays from the sun. Because the JWST's mirrors are made of beryllium--which serves its purpose beautifully in the low, low temperatures of space--this "heat shield" is needed. To give you an idea of the massive efforts being poured into this project, a huge cryogenic test chamber (a container as cold as space) was created just to test the effectiveness of the mirror, and outfitted with giant magnets that exactly and constantly counteract gravity.
No doubt, the Webb will make a splash when it is fully functional, so stay tuned!