These days, you'd have to look pretty hard to find a clamshell phone, many of which are not considered "smart". However, Samsung has been making a few of these clamshell style phones, and throwing Android on them. Samsung has only been selling these in China. After launching the SM-W2016 last year in China, they are now working on the successor, which is going by the model number SM-W2017 and using the codename 'Veyron'. Currently, there isn't much known about the device, but we do know a few of the specifications.
The Veyron is slated to sport dual 3.9-inch HD Super AMOLED displays, and will be powered by the Exynos 8890 processor. That is the same processor that is found in the Galaxy S7 (outside of the US, at least). Additionally, we are going to be seeing a 12-megapixel camera on the back, along with a 5-megapixel front-facing shooter. This rumor also states that Samsung will be using the same design as seen on the Galaxy S7, with a glass-and-metal build. No word on whether it'll be water resistant however. But that would be a pretty interesting spec for this clamshell smartphone from Samsung.
While there's no word on what OS it'll be running, it appears that Sammobile is thinking it is running Android. Which would make sense seeing as its predecessor did also run Android. There aren't many details available, in terms of when this device will be available or for how much. But it is pretty likely that it won't be available outside of China, similar to its predecessor.
Samsung is one of those companies that makes smartphones in all sorts of form-factors. Basically, throwing everything against the wall and seeing what sticks. The first clamshell smartphone, the SM-W2016, was likely an experiment for Samsung. To see if anyone was actually interested in a clamshell smartphone in this day and age. While we don't have any specific numbers for how well that model did, it obviously did well enough for Samsung to make another one. This is actually how the Galaxy Note lineup started out. It was an experiment for Samsung, to see if people wanted a larger screen with a stylus. And as we know now, they definitely did.