Google is now indexing Flash pages, so you WILL be indexed, but it is much harder to
SEO in Flash.
Also, 100% Flash sites take away many of the features Power Users use- If I am following something, and I see something else I want to investigate, I right-click to open the secondary item of interest in a new window, so I can follow that seperately- Flash sites take this option away, so I avoid them when I can as my options on that site are more limited. Also, Flash forces the user to watch all those silly animations, pictures, and movies. If I wanted those, I would have Google searched for Images / Video. I search for ANSWERS (Content). Most users could care less how pretty your site is if you don't have what they want, nor do they care (within reason) how feature-lacking your site is if you have exactly what they searched for in the first place.
Flash is a powerful ENHANCEMENT to site design, but it should not take the PLACE of your site's framework.
my .02