Via [url=http://blog.counter-strike.net/index.php/2016/06/14781/]the CS:GO blog[/url]:

[quote=Valve][CS:GO]
– Added new Gamma weapon case featuring 17 community-created weapon finishes and all-new knife finishes.
– Operation Wildfire Access Pass is no longer available for purchase.
[XP]
– New CS:GO players will get a significant earned XP boost multiplier in Recruit and Private Ranks.
– Competitive matchmaking for new CS:GO players is now unlocked sooner, as soon as they rank up from Recruit to Private Rank 2.
[PRIME BETA UPDATE]
– CS:GO accounts will be Prime if they have verified their phone number and achieved at least Lieutenant Rank 21 or have earned a Service Medal.
– Prime accounts can now select to search only for other prime accounts in competitive matchmaking.
– When matchmaking with a party lobby, all party members must be Prime to have the Prime-only option available.
[SOUND]
– New sound cue for shooting with low ammo.
– Upgraded sound fidelity, reduced distortion for Mag7, M249, Negev.
– New smoke sound to reduce interference with bomb defuse sound.
– New sound for text chat messages in party lobby.
[MISC]
– In classic game modes any money earned by a player mid-round will no longer be available for spending during the same round (i.e., SMG purchases are no longer possible during competitive pistol rounds).
– Suicide or disconnect compensation will no longer be awarded in warmup or during freezetime period.
– When controlling the bot and surviving round running out of time, the controlling player is now eligible to receive end of round money.
– Removed a legacy 2.5 seconds spawn grace period for players who reconnect to the round after freezetime is over.
– Increased upper limit on possible mp_halftime_duration values to 5 minutes.
– Added server convar sv_spec_post_death_additional_time that allows adding a delay for spectators between the death of a spec target and the switch to a new target.
– The convar sv_alltalk has been replaced with sv_talk_enemy_dead and sv_talk_enemy_alive.
– Classic Casual now defaults to team-restrict communication for living players.
[Mac]
– Fixed appearance of fonts in the community browser and console.
– Fixed some bugs with setting fullscreen resolution.
– Set all Mac players to use Raw Mouse Input by default since this is a better experience for most players. Players can manually revert to not using raw mouse input if that is what they prefer.[/quote]