Well, I went to upgrade from RC2 to the full version of 9.2 today and quickly found out that was not an option. Nowhere was I greeted with the option to upgrade
Not to be deterred, I decided to experiment and got my machine completely upgraded as far as I can tell using urpmi
A synopsis of what I did.
1) Mount all three ISO images using loop on /mnt/CDX
2) Remove all sources from urpmi
3) Add those three "CD's" as urpmi sources
4) urpmi.update -a
5) urpmi --auto-select
I had to manually update my kernel, but everything else seems to have upgraded beautifully

Took some time, but worked. I was quite worried about such a massive upgrade with an rpm base

but it all turned out well.
So those of you looking to accomplish an RC to full upgrade, this should work for ya.
Jkrohn