The smb backend interact with libsmbclient which has support for MS DFS shares but gvfs-smb does not work with them (on top of not automatically use Kerberos tickets).

Exemple 1 with smbclient :

$ kinit user@DOMAIN
Password
$ smbclient -k //server/DFS-Share
OS=[Unix] Server=[Samba 3.0.24]
smb: \> dir
.
..
Some Files   A  10000 Mon Jan 01 12:00:00 2008
Some Dir     D      0 Mon Jan 01 12:00:00 2008
smb: \> quit
$

Exemple 2 with GVFS :
$ kinit user@DOMAIN
Password
$ gvfs-mount smb://server/DFS-Share
User [user]: user
Domain [DOMAIN]: DOMAIN
Password:
$ gvfs-ls smb://server/DFS-Share
$