I've been AWOL for some time, but what I've heard in episodes 15 and 16 has been really cool... I remember I got hooked on some of the early episodes... anyhow, there should be a sticky thread listing all the songs that have been played so far (shouldn't be hard to do... I'd do it myself, but it's 5 am and I'd better go to bed... )
Then again, I started from the 1st episode but there wasn't the list of artists/songs that were on the first episode... and there isn't an episode... dammit! Does anyone have the first episodes to which the links are missing in the msrcast page?
Anyhow... a cool future theme (haven't checked if you've already done it) would be Symphonic Metal... from speedier/power-er metal ('hollywood metal' like Rhapsody)... to Slower more melancholic metal (like Estatic Fear, which is a cool mix of symphonic and doom, perhaps?)...
Or maybe a theme about groups that have included unusual instruments... Haggard has a whole orchestra... Estatic Fear's Matthias Kogler plays the Lute... Marcela Bovio, the vocalist from Elfonia (a group from my town) sings and plays an electronic violin...