Flash Tutorial on Sony's site
hdv_01 (http://pro.sony.com/bbsccms/assets/files/micro/hdv/flash/hvrtutorial/index.html)

Product Preview Video #1 (you can also find #2~#5) by Sony
YouTube - Sony HVR-Z5 Product Preview Video #1 (http://jp.youtube.com/watch?v=nUFOWbnlCEM&feature=channel)

Slow-motion sample (probably shot by Z5U) by Sony
YouTube - Sony HDV slow-motion demo from Sony USA (http://jp.youtube.com/watch?v=JaUI3pLeTTs&feature=channel_page)

Cool video by Sony
YouTube - Sony HDV products presentation (http://jp.youtube.com/watch?v=3VBG4IyH3ag&feature=channel_page)

Good footage to check DoF by user
YouTube - Second HVR-Z5U test (http://jp.youtube.com/watch?v=zRUMrNls120)

Low-light comparison by user
YouTube - HVR-Z5e v VX2100 Lowlight Standard def Shootout (http://jp.youtube.com/watch?v=RdTylCyR67A)

Enjoy !!