They may be more than 15 years old but I would still not consider them retro. Maybe I could give leeway to the Wii as it was nothing more than a overclocked Gamecube (right down to the graphics) that happened to have motion controllers but for the PS3 and Xbox 360 it's a little more complicated.
>today's controller button layouts, for lack of a better word, haven't changed too much from that gen besides having a upload button. Gyro in controllers has been a thing since PS3's Sixaxis (and you would be right to say that the layout of PS3 controllers is about the same as the PS2 and PS1's Dualshock right down to how you hold them)
>they had new hardware to seperate them from their predecessors (and you would again be right to say that early PS3s had PS2 hardware to play the games, but it didn't live long as future revisions of the console eventually gutted PS2 hardware)
I don't know if homebrew means anything for retro but the Wii isn't good at running PSX games the way PS3 emulates them flawlessly and to some extent PS2 games.