Perhaps the most mysterious addition to the PlayStation 4 controller is its touchpad. Not quite a touchscreen, we're wondering how developers will utilize such a unique (and odd) addition to the DualShock.

The upcoming PS4 version of Diablo 3 will use the touchpad in some way, although Blizzard is being a bit coy about how it all actually works. "Diablo 3 has a lot of cool inventory things," lead console designer Josh Mosqueira said in a new video. "Just the possibility of the trackpad is really exciting and we can't wait to dive in and make it as awesome as we can."

Watch: Touchpad will make the interface easier »

Happy birthday, Diablo III! You're one year old today. My, how you've grown! You do have the odd little accident now and then, and you're still not quite ready for fighting, but gosh, haven't you come a long way. And now, very kindly, you're offering bonus XP and Magic Find to everyone who celebrates with you, and $20 off for newcomers. You are a good little action-RPG, aren't you?

Read more: 25% stat boosts; 33% off the game »