Star formation at high redshift has increasingly been implicated in the process of IGM reionization, yet the mechanism and even definite timeline of star formation intitiation and cessation remain elusive given the evidence to date. I will review some of our results concerning the ionizing flux contributions of quasars and galaxies at z~6 and beyond, as well as ongoing searches for these sources in new deep optical/near-IR/mid-IR data such as ACS, UKIDSS, and Spitzer. The existence of early massive stellar populations at these and lower redshifts has begun to suggest the possibility of a regulatory role by AGN (among others) within young galaxies. I outline some galaxy selection and spatially resolved spectroscopic followup techniques that may allow the identification and separate examination of AGN and stellar components in deep galaxy surveys, to possibly catch star formation regulation mechanisms in the act.