It is possible that this image does not use standard steganography, so the chance of it needing a password is low. It is believed that any data may be hidden in plain sight, and is probably a plaintext message of some sort. Photoshop and a working knowledge of number systems are probably the best tools in this instance.
===Strange ._0X Jpeg's===
Recently I Downloaded the Year Zero desktop wallpapers and found 8 odd jpegs that seem to be not jpegs
they are called: ._01, ._02, ._03, ._04, ._05, ._06, ._07, and ._08
so at least knowing some odd things i opened them with notepad, 1-7 have identical info but #8 is different
It is full of code and such and has Adobe Photoshop cs3 written near the top. im not sure how much of a
lead it is but I found this strange to include files that are not in a wallpaper package.
link to walpapers http://yearzero.nin.com/wallpaper/index.html