So Darrell, it seems you know how to get around the OS backwards restriction.
Closeouts on the previous Mini are out there now and the price is about the same as the new Mini. Decision tree:
If Lion turns out to be a good thing for music servers, either HW choice is fine but the new Mini has more horsepower, so why not.
If Lion is not good for music servers, or at least initially, then the new Mini only works if I can install Snow Leopard on it.
If I can't install Snow Leopard on it, or if that would void the warranty, then a closeout earlier Mini is probably my best best.
Am I missing something?