Picked up a iPhone 5 on Friday (21/09) and was able to setup from my 4S backup (taken earlier that day). All my contacts, SMS, Apps, Email accounts, etc loaded sucessfully - except the Camera Roll.
I left my device connected to WiFi overnight in hopes of it downloading all of my pictures, but with over 24 hours connected, I was only able to pull down 30 or so images.
(Please disregard the low WiFi signal, this is using my work network just as a point of reference - home network was at full strength).
Since the first attempt of restoring from this backup, I have again wiped the handset and started the restore process again...but with the same results.