Seems to me that these are in a fixed position, which means that they will be at the phone manufacturer's discretion. Unless Google/Microsoft develop a standard (obviously, iPhone can do whatever the hell they want).
It will only be effective for gaming if they create a standard which is good for gaming. Also, phone manufactures may opt for a layout which favours other uses - photography, typing, whatever.
Still, something interesting to look for in the future.







