(Video of PRS-600 and 505 SIDE-BY-SIDE in the link)
I was thrilled to get it so early as well! It comes with 11 "books" installed, but really they are just samples and snippets. Nothing worth reading.
It does have the V3 of the Library software embedded, but it is apparently just a download application to the Sony web-site and it FAILS to install on either a Mac or Windows ("an error occurred while downloading software, please check internet connection and try again").
I actually bought two of these units. I'm sorry to say that one is certainly going back - my friend's first comment (an eBook newbie) was that the glare would give him migraines.
At any rate, for those of you anxious to see, here's some initial low-res pics and a video including a side-by-side comparison of the 505 and 600..