Fixed in IRC.

Yup, desktop is now running retail 10.5.6 thanks to this method (and nfoav8or's help)!

Could someone tell me how nfoav8or is getting the "Pro" theme for About this Mac? That looks awesome, and I'd love to have it.

Before you ask, yes, I've googled. A lot.

Is really necessary the Retail disk for this method.
And i had other question, kind newbie but i want to be sure. Course that i had to reformat the entire disk i had MBR partition scheme? There's nothing like migrate or something, eh?

Yes you need the retail disc. Distros have modifications - even when you don't choose any patches.
The most important reason though is the bootloader. It would mess up the EFI partition boot.
Surely in some future distros, there will be the new Chamelion 2 attached. It fully supports the EFI partion.
I am running a retail EFI setup for a few months now, with no major problems. Chamelion 2 RC1 works like a charm.

There is no migration, except you setup the new system on a new harddisc and migrate from the old. That works well.
Best practise is having a working second OS X on a spare disk and making the needed modifications from there
after installing via 132 boot.