The chat window was intentionally redesigned and modified. The intention is to have the Main tab with everything for your character and move anything else to separate tabs.
Main Everything that is visible and audible to your IG character.
NPC Talking with NPCs.
Tell Private tells.
Guild Guild chat.
Group Group chat.
Auction Auction messages.
System System messages.
Help The help channel.
The Main tab is supposed to show says, shouts, emotes, drops/pickups and base combat messages (start combat, nearly dead, killed). Basically anything that your character in the game would see or hear.
Having guild and group messages on the Main tab was my mistake and I will remove them this weekend. Also I will try to remove that annoying blinking of tabs when the message is already seen on another tab. I apologize for the inconveniences.
Not sure about tells on the Main tab, because they can be used both for IC whispering and OOC tells.
The All tab is not coming back, but in the next version we will most likely have the Main tab configurable so that you can pretty much configure it to be like the All tab was before.