A lot of current WhatsApp BlackBerry customers, who are paying annually to have access to the application, will upgrade to BlackBerry 10 when it comes out. It has been noted that WhatsApp does not currently have any plans to support BlackBerry 10 platform, which would leave all current users unable to communicate with their friends and relatives also relying on the application for cheap mobile IM communications. Considering that BlackBerry 10 platform allows developers to port Android application code, without any significant changes - this should not introduce a lot of development overhead and support costs will surely be justified by the still strong BlackBerry user-base.