I think the headset packages will begin to ship by the end of January as planned (possible the first shipment to the first few lucky pledges on January 30). They pretty much have the headset hardware design down, with just some minor tweaks left. I don't think they'll need extra time for that. Now, the lighthouses and controllers, that's a different story, but we already know those have been delayed a few months.
Of course, anything can go wrong, and I have no problem waiting for everything to be perfect. But I'm an optimistic type, and they've done nothing that leads me to believe the headsets will be delayed. Heck, they just sent out an email to us all saying that they want to start arranging production of our packages, and are just waiting on the last few people to fill out their surveys.