There are a lot of merits to the two PG lineup as long as your guys can guard their guys. Watching teams last weekend I noticed good teams are still doing this a lot.
Lillard is a point guard who can catch and shoot or drive, so he can also play off the ball when he needs a 'rest'. Semantics aside, he's fucking good.
I have always loved two PG's on the floor at the same time. Look at our 76'-77' team, OK yeah we had the best passing center of his era, but we also had three other guys on the floor at all times who could dribble and pass. A three guard rotation of Hollins, Davis and Twardzik to go along with Bobby Gross at SF made for great ball movement. With a SF like Nic, combined with 2 PG's you can see how well things move. I love it in crunch time.