Just stumbled upon the appearance changes on Google+ this am. I haven’t been able to find any officially reports on what the recommended upload size of the new cover image for Google + is, however in my own calculations it appears to be 1024 x 580.
I like the way it looks, although when you first click on the profile, they hide the top half (?- just a guess) You have to scroll up to see the whole profile image.
The other change they made today was to put your profile picture in a “circle” (cute eh?) and list the number of people who have you in their circles.
Just a couple small visual changes… As I encounter other I will keep you posted.
Click on the image to view my profile, and like it says I circle back…