I would recommend against using Flash anywhere on your web site except where it is absolutely necessary and then make sure the visitor is warned a Flash page will open if they click the link.
1. Although some search engines can now see some Flash, most can't so you may not get the site well placed on the Search Engines unless you use other indexing techniques.
2. There are a lot of people who don't have fast connections (especially those living outside major cities). Some even have a DAX box (thanks BT) which limits them to a maximum of about 28.8! Subject these people to Flash is, in my view, bad manners.
Flash, therefore, should never ever be used on the index/home/default page.
I will quite often leave a site rather than wait for the Flash movie to open (only got ISDN here), unless the site has something I am extremely interested in. I always click the Skip link on those sites as well.
As connection speeds get faster, then I think Flash will become acceptable. Until then, use something else.