I don't have much/any knowledge about Eberron or know what kind of 'feel' you had in mind for your urban druid... but the title alone got me thinking about a druid variant.
The distinguishing chaharcteristic of urban settings is (yeah yeah, buildings/metal/etc) PEOPLE!
So to create an urban druid you might substitute out a range of nature-y spells (virtually all of them I know, so a bit of work involved) and replace them with mental manipulation, crowd supportive, mood affecting type spells- and to add some urban flavour of course have some "non-natural" material manipulation spells (instead of Entangle with Plants, Ensnare with viscous tar) that kinda thing.
Of course a suitable replacement for animal companion would need to be found to retain balance but I can't think of something off the top of my head atm.
(Core concept: Rather than channeling natural energies that permeate the world- the urban druid channels the intellect/society generated energies you get from a dense population.)