I don't think they have any right to ask back things when they (the Egyptians) plundered the tombs, sold the artifacts to highest bidder - some times to the first, best buyer, destroyed and spoiled hundreds of historically interesting pieces, flooded archaeological sites... It is believed that 3/4 of the Egypt's history is still hidden in sand and under the modern cities and buildings. I say to mr. Hawass, first, dig up at least half of that, THEN you can start asking for things "back".
"However, the negative side is that the environmental and display conditions leave a great deal to be desired. Labels on some exhibits date from early in the century and many items have no labels at all."You might also need to actually DO SOMETHING about "the environmental and display conditions", before you start grabbing the artifacts. Also, where would you put them?
- about Egyptian Museum in Cairo
As it is now, people can go to Berlin and see Nefertiti, or to London and see the Rosetta stone - they don't need to come to Egypt and miss seeing these, because it's too crowded, both with artifacts and people... besides... it would cost me 1.500 kronas to get to London, 1000 kronas to get to Berlin and 3.500 kronas to get to Cairo... I'm sorry, Zahi, but I'd rather take BOTH the Egyptian Museum at Alte Museum AND British Museum AND have 1000 cronas left to buy souvenirs with... If I'd be American the prize difference is even bigger. They'd get 2000 kronas in pocket money. Besides, the admission to the BM is free... I think I should have the right to see true Egyptian artifacts even though I am poor.
You could also try to replace the things you want back with something. For example, it's not necessary that the obelisk at Place de la Concorde is just the old, original one from Luxor, make them a replica and ask if they'd be kind enough to accept another Egyptian obelisk instead of the one that should be in Luxor. In my mind it doesn't matter one bit whether it is in Luxor or Paris. Luxor wouldn't be any more amazing than it is now if there were two obelisks instead of one.
Also, Rosetta stone as the "icon of Egyptian identity". Bull. If the Egyptians cared about their "Egyptian identity", they'd kept their Egyptian language and writing alive, like the Jews managed to do with their unique language and writing through the centuries.