Not easily and no it is not a NAS.. it is missing several key aspects.. eg no backup, no raid, no dyndns, no vpn, no http,https, ftp, sftp or any other protocol you can dream up that would enable easy remote access. You can remote access using AFP which is fine if you have fixed public IP. And you can do it from a Mac using Lion and iCloud.. otherwise no. There is no other official Apple means to remote in.
Frankly if you want a NAS for remote access look at synology or QNAP .. the TC is a backup device for TM.. that is the purpose Apple conceived it for.. particularly wireless backup of Mac Laptops.