Microsoft is going to unveil new Lumia device on November 11. They have teased a picture on Nokia Conversations site that saying "Microsoft is delivering the power of everyday mobile technology to everyone. Come back on November 11, to find out more!" with a #MoreLumia hash tag.

Earlier there was some rumors and leaks about a new Lumia device which passed the Chinese TENAA certificate authority four days ago with the name Lumia RM-1090.
The leaked specs shows that it is an entry level device with 5"qHD display, camera with LED flash, dual SIM and the first handset to come with a Microsoft branding on the back.
This will be the very first Lumia device to be released without a NOKIA branding. Microsoft will unveil their first Lumia device on November 11 so stay tuned.