"The url of the images begins with us.media.blizzard.com/232309/
Why 232309? If we assume that the numbers correspond to the letters in the alphabet we get 232309=WWI ... ring a bell? :-) World Wide Invitational
23 = W
23 = W
09 = I
Anyway the "hidden" picture is called 04.jpg. (
http://us.media.blizzard.com/232309/_images/04.jpg)
My guess is that tomorrow we'll see a picture called 09.jpg, then on Wednesday 01.jpg ....
Today is 04.jpg = D
if Tomorrow will be 09.jpg = I (if its not, maybe not diablo at all Tongue)
Wednesday will be 01.jpg = A
Thursday will be 02.jpg = B
Friday will be 12.jpg = L
Saturday will be 15.jpg = O (June 28 WWI 1st Day, Good to announce here also.)
Sunday will be 3.jpg = 3 or three.jpg or whichever. = (June 29 WII 2nd Day, and B-day of Diablo, more better to announce here.)" Quote from Diablofans.com
Blizzard has had 04.jpg and 15.jpg so far which represents the D and O for Diablo.
Diablo 3 will be announced at the 2008 WWI. I'd bet money on this