NeverDie: Thanks for that link, it has some good information. The takeaways, for me, are that "Thread" is really Nest's "Weave" protocol with enough changes to bring in (a handful of) partners. It is Samsung's chip division that is involved--not their consumer electronics folks. So, at this point, the only potential consumer products are from Nest, Yale and Big Ass Fans. Not exactly overwhelming.
Work2Play, I'm not comparing Thread to HomeKit...more saying that Thread is going to get buried. Home Automation is currently a tiny niche market. While the Thread protocol might be very nice, it is not going to change that status. Apple, however, is going enable all those iOS devices to be a fun, sexy, home automation controller in the next few months. If an iOS user wants to dip their toe in automation, they can buy a thermostat, or a door lock, or a lighting product through (I presume) Apple's physical or online stores.
Under that scenario, Apple has the bits in place to move HA from niche to mass market. Whatever protocol they use (and it hasn't been announced at this point) will become the de facto standard. To reach back a long way, Postscript became the de facto standard for high end page description languages (PDL) after Apple included it in the LaserWriter printer. It was proprietary and there were lots of other PDLs before, but it became an important standard. Thread is likely to be part of the old niche market.
There are lots of ways Apple's Home Kit can fail (lousy, faulty or expensive products, major security breach, etc) but I think the ingredients are there to create a smart home market that doesn't now exist. BTW, there is no indication that Apple is making any of the smart home accessories. They'll sell iOS devices and take a cut on devices and software sold through Apple's retail channels. Whether or not the devices are solely locked-in to Apple's protocol is up to the manufacturer, I would think.
Craig