Light from the first stars and galaxies is substantially redshifted due to the substantial expansion of the universe since these early times. The redshifts of these sources are significant enough that it is not possible to look at these objects at visible (optical) wavelengths. Instead, one needs to move all the way into the infrared portion of the spectrum.
This is why the newest set of instrumentation for exploring the high-z universe will have exciting new capabilities in the infrared.
James Webb Space Telescope
The James Webb Space Telescope (JWST) represents the next generation of space telescope and should completely revolutionize our ability to image the universe in the infrared. It will have a 6.5 meter primary mirror, which would give it a significant larger collecting area than the mirrors available on the current generation of space telescopes (7.5X larger than HST and 60X larger than the Spitzer Space Telescope). JWST has a planned launch in 2013 and will be in operation for three years. It will positioned a million miles from L2 (the second Lagrange point around the Earth).
JWST will contain four science instruments with imaging and spectroscopic capabilities. These instruments will provide wavelength coverage from 0.7 microns to 29 microns. JWST will have significantly larger field of view than the WFC3/IR camera on HST (covering more than ~4 times the area) and significantly better spatial resolution (~0.13 arcsec) than is available with the Spitzer Space Telescope (~1.5 arcsec). Altogether, its exceptional capabilities mean that we will increase our capacity for discovery science by more than a factor of 1000. With JWST, we should be able to learn more about the high redshift universe (at times less than 700 million years after the Big Bang) in just a few hours of observations than we have been able to learn from all the HST observations taken to date.
Thirty Meter Telescope
The TMT (Thirty Meter Telescope) represents the next generation of large ground-based telescopes and is planned to have a total collecting area which is more than 700 square meters, more than 9 times what is available on the current generation of 10-meter class telescope. Other very large telescopes that are planned include the Giant Magellan Telescope and European Extremely Large Telescope.