RAKwireless is working on one afaik. They sent me a powerpoint presentation for it. Don’t know if I’m allowed to share though.
Its got USB + SPI (switchable with SEL signal) on a mPCIe connector and can have either SX1308 or SX1301 populated.
Just contact them if you want to know more. Should be having prototypes by now if nothing else came up, as I last commented on the specs at the end of October via mail - they sure would be happy to hear from more people asking for a product like this as their main problem was demand to make it worthwhile.
PS: It’s not using a standard mPCIe interface though, just the form factor, USB pins are the ones of mPCIe, omitting the other PCIe signals (like REFCLKx, PERP0x, PETxx, …) and adding some SPI lines as far as I can see. Don’t know if they can be swayed to implement full mPCIe compatibility at this stage and what that would do to the SPI implementation (which mPCIe doesn’t have) and their roadmap.