There's new evidence that Microsoft is planning to launch a new 5.7-inch Windows Phone device in both single and dual-SIM versions, at least in India. It comes from the import analyst site Zauba, which shows that the phones were shipped from Finland to India for internal testing on May 19.
There's also pricing info for both devices, which may or may not indicate that this new smartphone is in the mid-range. However, the Zauba listings tend to be inaccurate once the products in its database are officially announced.
Some sites are already labeling this smartphone as the Lumia 840 XL, but of course it's too early to see if that will be the actual name of the device.
In any case, it's possible we might have a new phone announcement in the near future. We will keep an ear on the ground for further developments.