We ended last weekend, and made the soup on Saturday. As far as roasing vs. not roasing, it all depends on what take you have on the raw foods thing. Either way, you will be cooking the veggies in the soup, way you will end up with cooked/heated veggies if you roast or not - and roasting DOES add lots of flavor. I have heard arguments for both the raw foods and cooking foods side - some people even say cooking makes some nutrients MORE accessable - Personally, I choose to cook some of my veggies for taste - like in veggie chili, soups, etc ... but I also try to eat raw veggies as much as possible.
One thing - I added Miso to the broth after our first soup-day. It added a LOT to the soup, but also adds some sodium, so it depends on what you're aiming for. Detour's soup is totally the way to go.