Well, I found a workaround too, and it's a bit simple, we can use it until the patch become available (for Intel Macs only).
In Finder, choose Corel Painter 11 application and get info (cmd+i). Select "Open using Rosetta", so it will re-write all the registration files.
Then launch Painter. It will ask you for the registration, I don't know if it is really necessary to register at this time (I did), but if you do, Painter will open normally.
So you can quit and you must disable "Rosetta" option, because you will loose performance using it. Then it will rewrite files again, register again, and all will work fine.
Here is the steps to clarify:
1 - Enable Rosetta and launch Painter;
2 - Quit Painter and disable Rosetta;
3 - Relaunch Painter, register and it's done.
Hope it helps.