No, it does not. It will only do it through the HDMI port. The only exception to this are "non-copyrighted" DVD discs (ie, DVDs that you burned yourself)
This is also problematic for trying to watch and Blu-ray disc (PS3 or any other player) due to certain copyright protection (such as the HDCP), which will prevent the PS3 on displaying the full resolution available in a blu-ray movie when using anything but the HDMI port and a non-HDCP compliant display.