  The exhilerating results from Swift in its first year of operations have
opened a new era of exploration of the high energy universe. The surge to
higher redshifts of the Gamma-ray bursts now imaged with increased sensitivity
establishes them as viable cosmic probes of the early universe. Wide-field
coded aperture imaging with solid-state pixel detectors (Cd-Zn-Te) has been
also established as the optimum approach for GRB discovery and location as well
as to conduct sensitive full-sky hard X-ray sky surveys. I outline the current
and future major science questions likely to dominate the post-Swift era for
GRBs and several related disciplines and the mission requirements to tackle
these. The EXIST mission, under study for NASA's Black Hole Finder Probe (BHFP)
in the Beyond Einstein Program, could achieve these objectives as the Next
Generation GRB Mission with `ultimate' sensitivity and wide-field survey
capability. Analysis tools for processing Swift/BAT slew data are under
development at CfA and will both test EXIST scanning imaging and provide new
data on GRBs and transients.
