Anyway, my thoughts --
Geometry: I like this map a lot. Except with the annoying pathing problem if the small ramp minerals aren't mined, it's really fun to play on. It's like Peaks in some ways, but with more money and more open. Also seems highly susceptible to gay zerg style.
Monty Hall: Incredibly innovative map. The rush distance is the longest possible, requiring the player to bring 3 workers all the way across the map even. At the same time, FE is much riskier since both the main and expo can be easily attacked. Hard to predict what will be standard on this map. Also, there'll probably be at least a few BASE RACES!
Nemesis: Haven't played much on this. Different from traditional maps in the backyard expansion and no non-island non-main expansions. A very large, flankable center should make some interesting strategies.