i'd like to see more actual mapsheet sets, ideally themed sets where the set can be combined in various fashions to make a much larger environment. like with Map set 7, where the 8 maps could be combined to make a massive coastal air and sea port.
an urban set with an approach similar to mapset 7 would be awesome, especially if the artwork and colors used match. you could have two sheets that combined make a downtown area, another 2 which make a parkland, another set with an industrial sector, and maybe 2 suburb/living space sheets.
combined with mapset 7 this would let you build a huge 4x4 play area for urban battles. or lots of variety for smaller battlefields.
similarly a rural set, with two sheets for a village/town, 2 for a large farm, and a mix of rolling hills, forests, and small lakes, all with some roads to link them, could be awesome as a way to fill in the gaps between the empty wilderness of the older sheets and the urban sheets of mapset 6 and 7.