I seem to remember reading that they're in the Snowdon Aviary for now. Did you go to London Zoo while you were in Europe? If not, it's on the edge of the canal opposite the African wild dogs and warthogs.
Right, I think I did read that somewhere actually. I did visit the London Zoo on my visit (was the first European zoo I went to) and did see the Snowdon, although I didn't walk along the outside at groundlevel, don't think I realised that you could. It was the very last place in the zoo we went to, and it was pretty late so we didn't spend long in the aviary.
Has it been said why the brolgas were moved to the Snowdon, and is it a permanent move?
This is pure speculation but, if they were expected to live with Emus, there may have been some friction. I understand Emus can be very nasty with cranes. Unfortunately, if these Brolgas are pinioned, they will only be able to use the lowest level of the aviary. This could be useful, as it would prevent damage to any ground-nesting birds' eggs or chicks on the higher ground.