NGST and GSMT: first cousins or distant relations?

A generation 8-m telescopes, particularly the Keck telescopes in the 1990s have played a crucial role in many scientific programs carried out with the Hubble Space Telescope. The Next Generation Space Telescope, scheduled for launch at the end of this decade, may form a similar relationship with the next generation of ground-based telescopes, for example, CELT, or the NRC Decadal Report's GSMT. Core science programs for ground-based telescopes are now becoming clear. Drawing on these studies, I will address the question of to what degree CELT, GSMT, and perhaps eventually OWL, will share the same important symbiotic relationship to NGST that HST and the 8-m telescopes have enjoyed, or to what extent they will carry out largely independent astronomical research.