It all depends. I'm all for QT'ing new fish. I agree with fishguy though, if you don't have a good QT, you're not doing anything good for the new fish. The point of a QT is to monitor the new fish, make sure they don't have any disease, and treat them if they do. That said, if I know where my fish are coming from, and trust the source, I don't QT them. I just got a shipment of Kerri Tetras from HN1 and SM. I didn't QT them because I know they do, and wouldn't have sent fish to me if they had been in the same tank as sick fish (at least to their knowledge). I also spend a lot of time at the store that I get my fish from now. I know of any sick fish. I also know how long the fish have been there. I have no problems putting their fish straight in my tank.
If you're not sure of where you're getting them from, I would most definitely QT them. You want to make sure your QT is cycled and that you keep up on the maintenance just like it's your main tank. And you still want to drip them when moving from the QT to the main tank.
JMO