You could get a quick version up pretty nicely I suspect using the Repository Module. If I recall right, team lead Steve has blogged about adding Flash or other video too. Anyway you can check that out at http://www.dotnetnuke.com/Projects/ModuleRepository/tabid/830/Default.aspx.

While it is a bit more complex in practise, a DNN skin is basically a single standard Default.aspx page (i.e. YOU have total control over it) which then you drop in a few tags like <menu goes here> or <right column goes here> or <footer goes here> within the page. DNN serves up the content from the database live, as each page is requested.

DNN 4.6 (hopefully) will play well with CSS, but for now few people that I'm aware of dare stray too far from tables - though it has been done. But aside from the tables vs CSS thing, you should be able to have any look you desire. Way too many DNN sites (including all of mine) are way too rectangular and boxy, but there is no reason they need to be.