Via the CS:GO blog:

The following changes are now available for testing in the Panorama CS:GO Beta Depot for Windows users.

• Repeatedly tapping the bomb resets the defuse UI timer properly.
• While spectating the bomb defuser, switching to another player no longer plays the ‘defuse failed’ fade-out animation for the defuse UI.
• ‘Buy Menu’ and ‘Use’ key bindings and will now go back one level in the buy menu instead of always closing. This matches the old behavior.
• Fixed an issue with upper/lowercase letters in some languages.
• Fixed team select music continuing to play after a disconnect.
• Updated crosshair style 0 and 1 to match the scaleform versions better.
• Updated the gradient background of the health and ammo on the hud a bit.

Chat:

• Added gradient backgrounds to hud chat panels and reduced drop-shadow for that text.
• The chat history window is now more translucent.

Scoreboard:

• Added ability to choose scoreboard stat for sorting by clicking on label.
• Fixed issue with resetting of some stats when the match was restarted.
• Fixed round survivor pips panel getting cropped in certain resolutions.