I don't see it doing more than 300k by Dec 31 2016.
It has a lot going against it. It is the most or close to the most expensive console peripheral ever released. That means it isn't gonna attract many brand new buyers as that is gonna mean about an $800 entry point. That means it is gonna rely on upgrades from existing users, which will still mean mostly $500 (pretty sure that 99% of users do not have an existing camera which is required), and that is more than twice as much as the kinect was, which had the advantage of cashing in on the tail end of the Wii craze, whereas the current feelings on VR are still pretty tepid.
I think Sony is trying to replicate the Wii, going as far as to artificially restrict the supply this holiday to give the appearance of it being hugely in demand, however I don't think consumers will fall for it. There will be a small core of loyal users who will buyout the initial small shipment or two, but after that I think it will fizzle out. Unlike the Wii, there is no pack in game, let alone something of the Wii-Sports caliber. A demo disc isn't gonna make tons of people go out and hunt for it, and none of the demos seen so far seem like they have any sort of lasting appeal.
There are already two superior VR systems, so a lot of the people who really want to experience VR with the current offerings mostly already have. The only way PSVR succeeds is if it differentiates itself enough in terms of cost and software offerings. Right now I don't think it looks like it is low enough in price to bring in a substantial base (it costs more than the PS4 did at launch for almost all current PS4 users), it will be canabalized by core PS users who would rather spend the dough on a PS4 Pro, and none of it's software seems much better than the other VR offerings.
If the world is really thirsting to throw down $500-800 en masse, I will be very surprised.