Who's filibustering what?

The more I look at this stunt that Harry Reid is pulling in the Senate, the more confused I get. From what I gather, it's going to be the Democrats filibustering, not the Republicans. And, I also gather there's a real possibility that the Republicans can cut it short almost immediately by issuing a quorum call. Apparently fifty-one senators are required to have a quorum. The Democrats don't have fifty-one people, so they can't make a quorum on their own. Bingo. So, the Democrats will get the worst of both worlds. They'll be called obstructionists for filibustering and they'll be ridiculed by having their tactic fail before it's even begun. I don't get it.