Though true, I doubt console games are going to get sophisticated enough that there'll be complex menus, certainly not in a competitive multiplayer game. Taking the most popular online games, I don't see where speech can be comfortably included instead of buttons. It's already used for communicating with teams mates, (well, reserved for that even if not used for that). Taking COD for example, what sort of voice commands will be appropriate? Maybe on respawn, choosing a loadout by name instead of scrolling through a list.
True for something like COD, a relatively fast paced FPS, more actions would slow down gameplay.
And in team based multiplayer you'd obviously need something to distinguish between voice commands and voice chat. A button dedicated to that perhaps.
Where things get interesting is in the realm of sports games. Perhaps not something like tennis or basketball. But something like American football where you can have set plays and, in real life, a quarterback can audible out of that changing the plan on the fly to another set of plays.
Or if RTS games were to ever have a hope of getting a foothold on consoles then voice commands could be key. Rather than a complex set of keyboard shortcuts ala PC, they could have complex controller commands or more structured voice commands.
If MMO's with a large variety of actions (versus ones with very limited player actions) are to, again make more than a token foothold, then voice commands could ease the transition.
Basically voice commands could allow for games to be run on consoles that are intrinsically hostile to play on a console controller due to the limited amount of buttons available and the relative slowness/difficultly of "pressing" multiple in game (on screen) buttons.
It's not so much about doing what consoles already do better. But allowing consoles to actually do things that consoles aren't good at doing due to the console controller.
Although in some cases it could make what consoles already do, better. Like for instance voice commands in ME3 allows players to do things better with voice commands than they can with controller alone. But again, you'd need some form of mechanism to distinguish between voice chat and voice commands in multiplayer games. But a simple button could be assigned to that. Push to talk or push to command depending on whether you want always on voice chat or always on voice command.
Regards,
SB