I think to bring more people through cultural cities there should be a jumping puzzle in each one like in LA.
DR – The queens observatory – Jumping on the planets and stars that spin around. Think frogger meets total wipe out.
The Grove – Some sort of underground luminous cave JP, maybe around the roots of the pale tree?
Rata Sum – Jumping through the rafters of a workshop, college libraries, golem battle arenas, you get the idea, kind of sneaking above watching asuras at work.
Black Citadel – Since it is built on the ruins of Rin, maybe some catacomb like JP with some lore hidden in there too relating to the GW1 mission?
Hoelbrak – A JP through a brewery where you need to use certain ales as a buff. Think speed buff for a big jump and then a shrinking potion to squeeze through cracks.
Just some cool ideas, lets hear yours!