This time around, there are two new instruments that astronomers hope to use, if the Space Shuttle's servicing mission works as planned. One is a spectrograph for analyzing ultraviolet light, that high-energy light that can be harmful to humans, but which contains a wealth of information about stars and distant galaxies. This spectrograph is called the "Cosmic Origins Spectrograph," because it will be useful for interpreting light from the earliest galaxies. More to the point, the light that we detect on Earth from the earliest galaxies is ultraviolet light that the expansion of the Universe has stretched into visible and optical light. So the Hubble's spectrograph will be used to explore more nearby galaxies (where we think we understand what is going on), and that information used to interpret the light from more distant galaxies.
Another new instrument will be a new imaging camera, more sensitive than the current one on Hubble. Like other cameras, this one will be able to take pictures in ultraviolet and visible light for studies of just about anything.
So, although these cameras are still on Earth, waiting to be launched by the space shuttle, we are starting preparations to use the cameras. It takes months for people to sort through the hundreds of proposed projects, select the very best ones (and some back-up plans in case one of the instruments fails or repairs don't work), and plan out an observing schedule. By the time that is done, we hope that the space shuttle will have safely traveled to Hubble and gotten back in tip-top shape.
Still, it is a little nerve-wracking to write proposals for broken cameras that we hope to fix, but may not get fixed, or for cameras that are not yet there and may not function exactly as advertised. And, since each proposal takes a lot of time if you want to do it properly, we hope that we are not wasting that time.