I don't know but I would think that the Detroit festival should have artists on it who come from Detroit (and that should be the majority of the line-up) and then a few who have an obvious affinity with its traditions.
I can see how DJ Spooky and The Roots fit into that as they are innovators who have challenged preconceptions of 'urban' music in the US. Another great hip-hop artist would be the consistently under-rated Prince Paul, who like Spooky and The Roots, does hip-hop while sustaining an interest and open-mindedness in electronic music culture. I just don't imagine that Woody McBride and Speedy J and Uberzone (who I have never heard of, if that makes me uncool, so be it) and all these other folks would fit into that paradigm. By the way to whoever it was who was asking about Davina's album on Loud a few weeks back, it's called Best Of Both Worlds and has just been re-issued on Loud (now distributed through Sony). C