Google has announced that their search algorithm now indexes flash sites and while it's good that buttons and the like can now be searched using Google, I still fail to find the merit of a site built in flash. If you search for something and happens to be on page X of someone's flash site, you'll still end up at he beginning of their movie when you land there from the search engine match. Maybe there's more to it that I don't get, but at this point this seems to be a moot point.
My favorite arguement for Flash sites vs. properly build sites is still this flow chart. Friends don't let friends use flash to build entire web sites.