I would be nice if they could support NTFS (both MBR and GPT partitions) for internal drives. Most NAS out on the market only supports HFS, EXT3, or some other Unix volumes. That's why I have stayed away from NAS, because I could not "easily" pull out any NAS drives and plug it into my "Windows" machine.
The only sub-optimal NAS that supports NTFS is GoFlex Home, which I did not hesitate to buy one even at retail price. I'm willing to support Seagate to develop better NAS for windows machines.
By the way, I have nothing against Linux or other HDD formats. But I'm just a Windows person. And I would like the flexibility of multiple usage and connectivity from a NAS.