I was completely scared of installing such update to 10.7.3, I don't have the precise % of success/KP(Kernel Panic), but anyone who can read this thread got a very strange feeling. So, I decided to give a chance for installing it. My real interest on it, was the new program called Messages(beta version, I believe) that makes possible the conversation through many iOS devices and MAC OS X. I was actually running 10.7.2 Lion, but it didn't allow me to install Messages. The only way is first updating to 10.7.3 then install Messages.
Of course, I was skeptical for this install process, because I didn't remember how I already installed the update 10.7.2. At that time, I didn't search any info, just install one package after the other, I didn't have any personal file, just the ones which are part of the OS X. Now, one big problem to face. I have some images, pictures, office files and NO backup at all.
I have a clear idea of running the update then use Multibeast to complete the process, unfortunately, I forgot to run Kextutilities to reassign the permissions...Believe or not, I got right after the upgrade, PANIC on CPU...(considering myself a dumb noob!!!!).
Lost all files...first thought!
I was able to recover them all!!!! I decided to reinstall the whole 10.7 Lion package from My installer partition over the existing 10.7.2. I didn't want to loose my files...
Since this point, I knew that I could boot the Lion partition, and then redo 10.7.2 over 10.7. Multibeast and rebuild permissions manually again. I reboot my computer several times, to make sure I didn't get anymore KP.
Good idea of mine, was to keep Installer Lion partition...
Last move, to install the package 10.7.3 combo. but just like a standard MAC, not used multibeast or anything extra...and boom! no kernel panic, sound, ethernet or anything like that.
Everything is working just fine, flawlessly.
Messages is working like a charm.
Advise: backup backup backup and clone partitions....