The third party Nitecore ULM240 battery charger is listed to support also the upcoming Leica M10 camera in addition to the M Typ 262, 246, 240, etc. This means that the new M10 will use the same battery as the M Typ 240 (BP-SCL2).
Nitecore ULM240 charger is not yet available for purchase (Nitecore products are sold at Amazon and eBay).
Update: there is a possibility for the Leica M10 battery to be thinner but still have the same length and width in order to fit in the charger. This is how the Leica M 240 battery looks – the body can be made thinner if the memory card slot is removed, which is unlikely:
