I have 2 1.5 T barracuda drives that formatted just fine (Raid 1)
It seems that this took less than 15 minutes total.
How long did you wait before aborting?
There are some notes in the firmware posts that you need 1.03 to use 2T drives.
You get to your firmware section via the web interface (TOOLS Tab, Firmware on left)
I think new systems ship with 1.03 now (mine did).
- Ken