Well, I was testing different scenarios to see how this works before anything happens.
I formatted a new 2 TB wd20ears to be used in standard configuration - no raid or anything. All OK. Can copy files, can delete them, all works as expected.
Moved the drive out and put it into a LaCie Poulton case I wanted to know if it could be read. Connected to OS X Snow Leopard - not recognized. Should be 'cause it's ext2, or so I thought. Loaded a Linux VM in virtual box, and Linux cannot access the drive.
Checking with OS X Disk Utility the drive shows 3 partitions (and some empty space) all formatted in FAT (wtf?)

So I cannot access the data without a dns-321 and the partitions are not ext2.
I wonder if it may be the case (has usb, firewire and e-sata) tested FW and USB and result is the same.
Has anybody been able to access the date using an external enclosure or dock or whatever...?