looks like they've slightly tweaked the notification lock screen again.
Image
compared to iOS 5 beta 2 and 3, where the notifications did not have any borders on the sides (see image above) for the notifications stack, beta 4 seems to have added borders to the sides of the notifications stack on the lock screen... a tweak i don't necessarily agree with -- looks out of place, imo
regarding photos:
- as mentioned before, photo albums will need to be re-synchronized with iTunes
- camera roll seems to have been added back (i'm assuming it's because i've done periodic iCloud backups)
- photo ordering in the albums and camera roll seems to have been corrected.
other than that, iOS 5 beta 4 seems to be pretty smooth so far; no bugs/crashes yet. we'll see how it goes, as it has only been a few hours with the new beta release.