Vegas Tripping is reporting that Sahara will announce tomorrow morning that the property is closing.
For the past few weeks there have been some pretty strong signs and rumors about the possible closing of the hotel. Two of the towers are already closed, along with the buffet and most of the restaurants. I believe most (if not all) of the shows have also closed or relocated in recent months.
The biggest problem with the property is probably the location. There isn't much happening that far north on the Strip these days. In better times Sahara would be able to compete by offering low room prices. Because of the economy most of the hotels in Las Vegas have great deals, so there is little reason to stay at Sahara.
UPDATE - March 11, 2011:
As expected, the press release announcing the closing was made public today. May 16th will be the closing date. The reason for closing: "Sahara was no longer economically viable." The company left the possibility for re-opening on the table stating that they would "Assess a variety of options for the property, including a complete renovation and repositioning." I think it's pretty obvious that won't be happening anytime soon though, if ever.