I apologise in advance because this is kind of a semi-rant, feel free to skip it since it doesn't adress any of the posted suggestions, though I like the mentioned features that Tom talked about.
When I think more about it, then I feel like we are missing the core problem of this whole thing. We must ask ourselves: Why are users even posting speedpaintings in the flash portal? To me, the answer is very simple. Out of all the main portals, it is the one that offers the most exposure for new artists. Let's be honest: when you are a new flash artist, then in the most ideal outcome your stuff gets frontpaged quickly and you will probably win a Daily award, which gives you the ability to post on the frontpage, so that from now on you can promote your art pieces and audio on your frontpaged newsposts.
As for other artists? Post the best painting in the world and it doesn't even appear in the art portal. You have to make 3 more art pieces and even then you probably have to wait for a long time to get scouted. When I look at the frontpaged art, then almost all are from already established artist that have been making art for years.
Same goes for the audio portal. The lack of both views and reviews there is a known issue when you read feedback from audio artists and the low amount of votes in combination with 0-bombers scares people away to other sites as Soundcloud.
And that's why we see speedpaintings and "music videos" with the song and a fancy image in the background in the flash portals, because all other parts simply leave new users completely in the dust and don't offer enough feedback. Same goes probably for users who are either exlusively users who produce drawings or audio and notice that their stuff gets less views than stuff in the flash (or movie) portal.
The problem with this though (and I don't claim to be right) though is that there isn't a simple solution for it. You can't force more views for the audio and art portal. And there is also the problem the stuff even in the flash portals takes days to pass. To be honest, I dislike to leave this negative post because the site is so great but that's how I feel about this whole thing. The core issue is a lack of views, which is more apparent in the less visited art and audio portal.