can I run an external display off the new LaCie 2Big Thunderbolt.

I currently run FCP 7 on a brand new MacBook Pro. I use the Thunderbolt port into a Thunderbolt to VGA adapter (third party) to run an external Asis 27" display. It all works quite well. But...

Right now I use a LaCie d2 Firewire 800 external HD as my scratch but would like to upgrade to the new LaCie 2Big Thunderbolt. I want to then run my external display (still using the adapter) off the second Thunderbolt port on the 2Big. Is this possible? My local Apple authorized store was very sceptical although they had never tested it, in fact, they haven't even sold a 2Big yet.

Has anyone done this? Am I going in the right direction. I don't want to pop for the 2Big (+$500) and find out the setup can't be done.

Thanks