A conceptual design for the Giant Magellan Telescope is being developed based on a primary mirror with 7 large segments to be fabricated using the borosilicate honeycomb mirror technology developed at the Steward Observatory Mirror Lab. A number of key instrumental capabilities have been identified by the Science Working Group. It seems likely that the instrumentation for wide-field imaging and spectroscopy in the optical and near-infrared will have the greatest impact on the optical and mechanical design of the telescope. A number of conceptual designs for wide-field imaging spectrographs and wide-field fiber-optic spectrographs are being investigated. Some of thse designs incorporate wide-field correctors. In addition the opportunities for ground-layer correction using a Gregorian adaptive secondary mirror (which is conjugate to a point less than 200 m above the telescope) are being actively considered, and a program to empirically test the prospects for ground-layer compensation in progress.