I seem to be on BRS-EWR more this year than in the prior 5 combined. I'm out again on Monday morning's 77, if anyone's headed Stateside.
The original 2 flights Mon-Fri BRS-BRU were appallingly badly timed for anything other than trips to BRU. The 3x (almost) daily becomes a viable feeder into US/European connections at BRU, and I think it's this, along with SN's entry to Star Alliance, which has boosted numbers on this route. At the same time, cutting inventory is hardening fares and driving yields. And SN hasn't been a cheap airline since it stopped being Sabena.
In regards to a German route. I think it might be complicated. When LH took control of BD, they poured BD craft and crews onto LH/LX routes, and I think this might have caused some umbrage for LH. I vaguely remember seeing a protest from the LH Pilots' Union that LH were hauling in "cheaper foreign crews" to operate existing LH routes. Since then, I notice that LHR-TXL has gone fully BD, and that the BD aircraft has gone to a brand new LH route (LHR-DRS).
So, reading between the lines, I think there might be a reason why a BRS-FRA/MUC route might have to be "BD, operated by BD" as opposed to "LH, operated by BD". (Same from LBA, I guess?).
The BRS-FRA launch in March 2008 coincided with LH's (IMHO ill-conceived) £49 o/w fare promotion. I suspect that meant they artificially boosted E inventory (the lowest class) on the route, combined with a 98 seat aircraft. If they come back again, I'd be amazed if they released any E/L/T inventory on a 48 seat aircraft at all - my hunch is lowest short haul fares would be W, and there'd be some U/V avails for combination with long-hauls. So no chance of a sub £220 r/t to Europe. (LH's fuel surcharge is also a pretty painful £25/sector, which is £100 in fuel alone for a standard 4 hop Europe trip).
So, fingers crossed to welcome BD (Regional) to BRS....