LH have the connecting traffic as DUS is a focus city with three long haul based a/c and a number of short haul. FR haven't really affected the current DUS figures so must be serving a different market.
I would guess BE would miss out. They should stick to wiping out small regional airlines as opposed to taking on the real big boys if I am being honest.
U2 will do well with low fares and business timed routes which these flights look very much like.