Site content is there to serve a purpose.
It should, in mu opinion, help to deliver your message, improve the visitor experience and add value to the site/visitor experience.
Video, unless very, very carefully implemented, often does none of the above and only makes people go and visit another site. In particular, dial up Internet users still stuck on 56k modem access (aka the majority of UK web users) won't thank you at all for including video files on your site unless they ae incredibly small.
Without a lot more detail on your site, its content, its target audience, the size of video file(s) you would like to include and what that video footage would actually do in your favour that static content cannot or does not do, it is almost impossible to formulate an answer to your question.
My rule of thumb in almost all instances is not to include video files and to make Flash animations small, to the point and relevant to specific aspects of the site. I also avoid animated GIFs like the plague.
Just my thoughts.