Two of the largest criticisms levelled at AoS were the lack of lore and the inability to use older models outside of some pretty dated warscrolls. The new Battletome for the Cities of Sigmar addresses both of these points in spades! Firstly look at all the amazing middlehammer miniatures featured that now have warcrolls and, we hope, some of the great faction improvements that we have seen from other battletomes in the AoS v2 cycle.
But even more than that you can give extra abilities based on which city you choose your army to be representative of. This sees a band of men and elves (aelves), and dwarves (dardin) work together to defend their city. Not only does this have a wonderful Italian City-State vibe to it, but the lore that will describe each city should finally give us an understanding of what exactly we are going to war for. This will hopefully enrich the lives of the common folk a little more.