Personally, I waited for that version several months already, hoping that it will resolve the slow problems I had on my personal laptop, as described on my previous post. Even changing the Kernel version, never solved the problem completely.
Here my update experience on three systems (all were 10.10).
Desktop PCMachine gots stuck and hang during the upgrade process.
After rebooting, when trying the use the new Grub entry, it claims that my hardware doesn't support Unity.
After a second boot, entering the Previous Linux entry, my old 10.10 system started up perfectly and advised about a partial upgrade.
The upgrade continued smooth and left my system at the end with a running Natty.
Only my Chromium isn't usable any longer, but that's another story.
Dell home laptopThe 2nd, a smooth upgrade, without any problem.
First I downloaded the ISO image, and mounted the burned CD as software source, so most of the packages hadn't to be downloaded from the net.
After upgrade, the slow problem was gone, finally I have a fast system again, even compiz effects are usable again.
Great, all my expectations have been reached.
Lenovo office laptopMy last system hang too during the update process, it blocked with the screen-saver and I wasn't able to enter the desktop, so I couldn't see where exactly it got stuck.
Rebooting the system, first showed that Grub hadn't been updated yet, and even worse, my old system didn't booted up.
My root partition didn't mount correctly.
Inspecting with the SystemRescueCD (I have an entry to it's ISO in my Grub boot menu as explained in this post) revealed that the filesystem hadn't been damaged, all files where there.
After some investigation, I found this discussion about a serious design flaw in the Upgrade Process which could lead to that situation.
I could recover with the mentioned commands as seen below.
Recovering from not ready yet or not present root partition
mount -w -o remount /dev/sda1 / dpkg --configure -aOnly one package made trouble, winbind, so I removed it with aptitude purge winbind, then run the dpkg command again and finally rebooted into a running Natty system.