The iPhone Duo went on sale at Apple Store locations worldwide on October 23, according to Apple.
That is the whole announcement. The company called the device "highly anticipated," which is its own description, and gave no price, specifications, storage options or sales figures. It also did not say which countries received stock first, or whether carriers and other retailers had the phone on the same day.
The gap is informative. A release-day post like this mostly confirms that a product now exists on shelves. Anything about how the Duo differs from the rest of the iPhone line has to come from somewhere else.
The timing is also worth a note. Apple's iPhone releases have traditionally landed in September, so an October debut sits outside that familiar window. Whether that reflects the nature of the product or the company's scheduling, the post does not say.
The open question is what the first independent reviews and early sales numbers show, since those will supply the detail Apple's own announcement left out.