played each race on a quick trial run. so far i am likeing it. zerg got a roach, protoss got collosus, & terrans got a unit called thor
you can hotkey upto 24 units per key
Much more than that actually. It shows 24 on the bottom but there can be many panels of 24 up to I believe 5, meaning 120 units.
Races got more than 1 new unit each too, they have a half dozen or so new ones each, most of which are similar to but different than old ones that were replaced. Though some were just outright taken out with nothing similar in it's place, and a few were added that are completely new.
Zerg
Devourer --> Corruptor
Guardian --> Brood Lord
Defiler --> Infestor
Infested Terran --> Baneling
Sunken/Spore Colony --> Spine/Spore Crawler
Remaining: Drone, Zergling, Hydralisk, Mutalisk, Ultralisk, Overlord
Gone totally: Lurker, Scourge, old Queen
Brand new: Roach, new Queen
Terran
Firebat/Vulture --> Helion
Medic/Dropship --> Medevac
Goliath --> Thor (supersized)
Valkyrie --> Viking
Science Vessel --> Raven
Remaining: SCV, Marine, Ghost, Siege Tank, Battlecruiser
Gone totally: Wraith
Brand New: Marauder, Reaper, Banshee
Protoss
Dragoon --> Stalker
Corsair --> Phoenix
Reaver --> Colossus
Shuttle --> Warp Prism
Remaining: Probe, Zealot, High Templar, Dark Templar, Archon, Observer, Carrier
Gone totally: Scout, Dark Archon
Brand New: Sentry, Void Ray, Mothership, Immortal