I'll be a monkeys uncle if this deal doesn't get done with at least 50% tendered. The arbitrage traders will make certain of this.
If I had to pick an exact figure I'd guess 72%. If anything else, higher.
If not, I do highly doubt that Luxor would liquidate their holdings as promised. That would be the dumbest thing ever, and they seem pretty smart to me.
Of course, I've proven I can be the dumbest guy ever - and I've put out my predictions to see if that's true!