Well, by the ironies of the modern filibuster, this one has lots of fireworks and looks like what a lot of people think a filibuster should look like. But it's precisely because this one actually has no teeth that they're resorting to the old fashioned system.
So here's the deal.
It's widely assumed that Harry Reid can get get over 60 votes to get cloture on schedule a simply majority vote. In other words, the GOP doesn't have 40 votes to derail John Brennan's nomination as CIA Director. But Rand Paul can do a one man talking filibuster and delay even that as long as he keeps talking and keeps holding the floor. He's done it for four hours so far. How long can he go?
For Paul, it also gives him the platform to discuss his civil libertarian arguments against drones.
Thus far, he's enlisted Sens. Lee and Cruz to assist him with short breaks.