Soundwave on 29 May 2013
I'll leave the current gen stuff out.
PS4: 100-120 million
XBox One: 70 million
Wii U: 36 million
3DS: 95 million
Vita: 20 million
This generation will see a general decline in overall users from the last one, or perhaps really it's more of just a normalization as casuals move away to smart devices.
