  We describe further results of a program aimed to yield ~10^4 fully
characterized optical identifications of ROSAT X-ray sources. Our program
employs X-ray data from the ROSAT All-Sky Survey (RASS), and both optical
imaging and spectroscopic data from the Sloan Digital Sky Survey (SDSS).
RASS/SDSS data from 5740 deg^2 of sky spectroscopically covered in SDSS Data
Release 5 (DR5) provide an expanded catalog of 7000 confirmed quasars and other
AGN that are probable RASS identifications. Again in our expanded catalog, the
identifications as X-ray sources are statistically secure, with only a few
percent of the SDSS AGN likely to be randomly superposed on unrelated RASS
X-ray sources. Most identifications continue to be quasars and Seyfert 1s with
15<m<21 and 0.01<z<4; but the total sample size has grown to include very
substantial numbers of even quite rare AGN, e.g., now including several
hundreds of candidate X-ray emitting BL Lacs and narrow-line Seyfert 1
galaxies. In addition to exploring rare subpopulations, such a large total
sample may be useful when considering correlations between the X-ray and the
optical, and may also serve as a resource list from which to select the "best"
object (e.g., X-ray brightest AGN of a certain subclass, at a preferred
redshift or luminosity) for follow-on X-ray spectral or alternate detailed
studies.
