Does Solaris Intel support multiple heads?

No.
A commercial X server from
Xi graphics, http://www.xig.com/
supports multiple heads.

Dual-headed monitors will be built-in Solaris 8's Xsun
(Xinerama, X11R6.4), but that works on Sparc only, not Intel.

XFree86 does not currently support multiple heads,
though the feature is on the wish list for XFree86-4.

[Thanks to John Groenveld, Alan Coopersmith]

ASGAUR