Proceedings of the "X-ray surveys, in the light of the new observatories" workshop, Astronomische Nachrichten, in press (4 pages, 5 eps figures, uses an.cls).-- XMM-Newton Survey Science CentreWe present preliminary results on the XMM-Newton Survey Science Centre medium sensitivity survey (XMS), with 0.5-4.5 keV flux limit 2x10^{-14} erg/cm2/s. At present, 19 fields have been examined with a total of 239 X-ray sources. Identifications for about 2/3 of these reveal that type 1 AGN dominate, but type 2 AGN, absorption-line galaxies and clusters as well as stars are also present. We also discuss on a few X-ray selected Broad-Absorption-Line QSOs found in this survey.Based partly on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and the USA (NASA). Partial financial support for this research was provided by the Spanish Ministry of Science and Technology under projects AYA2000-1690 (XM, FJC, MTC, SM) and PB98-0409-C02-01 (IPF).Peer reviewed