Well, @upleaks has just shared a new set of images – rendered ones, actually, which does seem to back up the theory that there will be silver and gold colored models of the HTC One M9 Plus. The HTC One M9 Plus render does have some minor differences with that of the HTC One M9, where the button might just replace HTC’s standard on-screen navigation scheme, or in some way, supplement it.
Apart from that, the huge round camera located at the back will definitely be different from the square sensor that is present on the HTC One M9. There seems to be a dual-tone silver version as well as a gold model of the HTC One M9 Plus in the renders, and both handsets happen to feature the China Mobile logo printed on the backs.