ALL key configurations will be overwritten. If you've bound your keys different than default, you must do it again. This is to open for the two new keybinding functions we've introduced. These are remapping the mousewheel to different buttons(CrossCom), and a new key "u" to toggle chat on and off in multiplayer
Multiplayer has recieved stability updates and fixes. We've found and fixed a number of issues that could cause disconnects, worse performance over time, and some crashes
You can no longer be a "ghost" in multiplayer, throwing grenades to fake "fatal accidents"
You no longer have to press "Enter" to confirm input in the multiplayer interface
Please note, this patch should not be confused with the planned "content" patch that is supposed to be released sometime in June. That patch will add plenty of new content to the multiplayer portion of the game (not sure about the single player) such as new Co-Op missions, full on Deathmatch and several other multiplayer modes that did not make it in before release.