Google announced
some Google+ changes last week but some of them were rolled out gradually and I couldn't see them.
The Google+ notifications button looks different: it's now a bell. The number of new messages is more subtle and looks like iOS badges. The new notifications tray separates the messages you've read from the messages you haven't read yet. There's a new button that lets you "mark all as read" and a funny message: "All caught up!", but you can also mark as read a message by clicking the small "x" icon. All of this reminds me of Google Reader.
Thumbnails are bigger and you'll sometimes see 4 of them for each message. The notifications tray now supports infinite scrolling, so you can read all your messages, and Google remembers your state when you close the tray. You'll no longer be able to use the arrow keys to navigate when you click the bell icon, but the keyboard shortcuts start to work when you click one of the messages (you can use j/k, left/right, up/down).
These aren't all the changes: "When you read a notification on one device, we'll mark it as read on your other devices. Likewise, dismissing a notification (with a swipe or a click) does so everywhere, so you can say goodbye to annoying repeats."
Just in case you want to see the old interface for notifications, here are some screenshots:
And here's a cool "jingle" animation from the new interface:
{ Thanks, Garfield. }