The APEX High Resolution EUV Spectroscopic Explorer

EUVE and other missions such as the ROSAT WFC have left a tremendous legacy on which we would like to build. The termination of the EUVE mission has left a glaring hole in the spectral coverage of space missions and the EUV astronomy community without a general observatory class facility. So where do we go from here? What scientific problems should (or could) a new guest observer space mission address and what are the technical requirements for such a mission.