So, it seems clear that the high redshift universe, just like the local universe, is full of dust. This dust will mop up all the optical and UV light produced by star-forming galaxies, and re-radiate it in the far-IR. So, we need a good, sensitive far-IR satellite.
This is what SIRTF (the Space InfraRed Telescope Facility) will be. A cryogenically cooled satellite capable of both imaging and spectroscopy from 3-180 m, it will have sensitivities two orders of magnitude better than anything that has flown before. It should be able to see normal galaxies, regardless of their dust contents, out to redshifts beyond three, and it will pick up starbursts out to far beyond redshift 5. It will be able to measure the star formation rate of the universe as a function of redshift throughout most of its history.
This awesome instrument, the last of NASA's `Great Observatory' program, must go ahead. It will do so much exciting science in all sorts of fields. The optical astronomers will doubtless say that it isn't needed: that they have already discovered the answers. Your answer to them must be DUST! Get out there and show them the evidence for dust in the early universe!