The version of gpio-dev we've come to know (and has been immortalized all over the wiki and in Atmel app notes) is an AVR32-specific thing maintained out of tree. The time has come for a generic version and there are discussions now on how to design the interface.
What I'm hoping is that anyone using gpio-dev now can tell me what they're using it for, what's good, what's bad etc.
Also, if you're using it for button inputs why aren't you using the gpio_keys or gpio_mouse driver? If you are running indicators (eg LEDs) off them why aren't you using gpio-leds? And of course valid responses to these questions may be things like "too complex" or "I didn't know they existed".
So please, let us know what you want to see in a new userspace gpio interface!