I wonder if there are any references to Raychem, who was the original tech company that owned the land the site is on. Then again, all FB employees have to do is look across the street at the carcass of the company, which TE Connectivity (formerly Tyco) has left after it gutted it post-merger.
Less of a tribute and more of a warning. Other signs of Sun—logos etched in glass doors, for example—have been left untouched on campus, to remind employees of the frailty and impermanence of technology's ruling companies.
I still work on an old Sun (occasionally), but only because I need this one piece of software and the person who wrote it died, so it's unlikely to be upgraded any time soon.
It's like seeing the rubble of an old casino in Vegas.