I also noticed today that the .sdc file for the CVI is added automatically in Quartus II 10.0. I also checked the VIP user guide, and it still indicates you need to add them manually. It only mentions adding SDC files for CVI and CVO, however I searched my install folder and found all of the following:
C:\altera\10.0\ip\altera\clocked_video_input\alt_vipcti100_cvi.sdc C:\altera\10.0\ip\altera\clocked_video_output\alt_vipitc100_cvo.sdc C:\altera\10.0\ip\altera\deinterlacer\alt_vip_dil.sdc C:\altera\10.0\ip\altera\frame_buffer\alt_vip_vfb.sdc C:\altera\10.0\ip\altera\frame_reader\alt_vipvfr100_vfr.sdc I didn't try all of the cases, but at least for the frame buffer (VFB), the sdc file is not added automatically.