I have a XVR-100 and a USB card installed in my E2900. To enable the graphical console login in Solaris 10 I have done the following post installation:
# svcadm enable
# ln -s /dev/fbs/pfb0 /dev/fb
# fbconfig -xserver Xorg
I did repeat these steps after another install, and had some trouble. There may be a step missing but it might provide a clue to someone else in the future.