The base of The Stardust sign has been taken down. Prior to the implosion in March 2007, the main section of the sign (the famous neon top) was removed. Since then, the still considerably large base remained; it's two vertical arms (which no longer held a sign at the top) rising far above the construction site fence.
"Oh, that's where The Stardust was."
Very often, these sort of signs remain standing for quite a while - (many years in some cases) even though no building remains.
The El Rancho sign was removed a few weeks ago, years after the place disappeared. [The second El Rancho, to be clear.] Turnberry Place had for some time hung a banner over the sign, until a wind storm took it off, revealing the El Rancho sign beneath. Now it is gone altogether.
A very noteworthy sign remains at the south end of The Strip. The sign for the Glass Pool Inn. It's on the same side as the defunct Klondike, just a little north. Some of the movie Leaving Las Vegas was filmed there. All that remains is the sign.
I understand that in the 70s, the famous Welcome To Fabulous Las Vegas Nevada sign was dark. It was turned off. The owner of The Klondike took it upon himself to repair and pay to have the Welcome sign turned on.
Now it is The Klondike which is dark, and the Welcome sign is lit and visited every day and night.
The relative speed with which The Stardust sign has been taken completely down is soon going to be surpassed by the construction of Echelon Place.
In the accompanying photos, the difference in The Stardust sign from last week to this week can be seen.