this is quite a debate. nice one!
i have my take though. i used Flash for 5 years. one thing i always discourage my client to do, Intro, that is so meaningless.
with the previous point, I disagree with the fact flash is heavy. from my experience, I keep all my flash + html file below 50k. so more of the time, my total site was only less than 100k, which splited into like 5 to 6 swf, which make it load very fast. Hence, I seldom use preloader in my flash.
for Flash Player issue, this is even more interesting. I realised that Adobe have new strategy on deploy the latest Flash Player 9. it used to be the player was deploy together with the software, say Flash Player6 was only available together with Flash MX software. but, for FP9, it was available for download 1 year before the Flash CS3 was launched recently. which means recently, when Adobe launched FCS3, they start to tell developer that already 90+% of web browser already added FP9. and that is good news.
because you can use Flash with XML, I think is just the matters of planning that make Flash easily update-able. I create a dynamic swf that read xml to update my interface, so everytime i have new link, I just upload the file and update the detail in my XML(which is just copy paste and all text based) then wala! done.
But one serious issue currently is SEO, which I agree with everybody that is almost impossible to make it happen compare with simple html. But I think Adobe is working hard on this, because they are loosing their grib to Ajax and other web 2.0 runtime.
my 2 cents. :)