The game is releasing only with 8 maps, 3 of which we played in the beta. Previous games launched with many more.
The game is releasing with only 1 game mode, there is no option for annihilation or victory point control.
There are only 3 races at launch, other games came with 4.
Races have less unit variety than previous games if you count combat line units while excluding workers/commanders/heroes/elites.
Various unit types are missing because they have been made into elites. (Wraithlords, Warp Spiders, StormBoyz)
Where are late game units like land raiders, avatars, squiggoths/battlewagons, flashgitz?
Units are not as customizable as before, why can't I upgrade my sluggas with flamers or my tactical marines with rocket launchers?
SM have unit variations split off instead of just being allowed to upgrade. (Scouts > Sniper Scouts, Hvy Bolter Devs > Las Devs, Pred Destructor > Pred Annihilator)