I have seen a bunch of articles on this in the last few days as well. My personal experience was that my iPhone4 and my iPad2 both updated fine on the day after the release of iOS 5. On the launch day my iPhone4 upgrade attempt took forever and ultimately failed. I really like the new iOS 5 features a lot. However, I've read a bunch of articles suggesting that various things that were on the device before the upgrade were lost after the iOS upgrade. The iCloud commentary has been less than kind in the press. I know attempting to do the iCloud backup from both my iPhone and iPad2 as part of the startup configuration after the upgrade failed on both devices. I said backup to my computer and everything else wwent fine.