Here's a good weather vane for the gaming industry: ask people what they'll be taking on the plane as they fly to the Game Developers Conference. This year, the amount of DSs and PSPs may be at an all-time low as people are simply playing games on their mobile phones or tablets. We no longer have to carry a dedicated gaming device to play a first-person shooter, real-time strategy game, or even a dungeon crawler, and many of us are moving on.

It's not that games on phones or tablets are better than what you see on Sony and Nintendo's handheld systems—it's that for many travelers they're good enough. People need to justify the weight and bulk when they pack things, and if they are already carrying something that can play games, why bring a second gaming-only device? Before every big conference the call goes out on Twitter, asking what iPhone games people should buy for the plane.

These games can be both casual or hardcore, they usually cost under $10, and they play on a device that you're already packing. New DS games cost around $30, and you're going to need to bring yet another device, and perhaps a charging cable. The 3DS isn't helping things, with a system that offers limited battery life and games that are even more expensive.

I'll be the first to admit that this is a trend that's hard to track—it's largely anecdotal—but at this year's DICE everyone was talking about smaller games that play on devices that are not primarily gaming devices. Even those who make the larger, higher-budget games for our consoles—such as the executives behind Blizzard and Bioware—are spending their time playing games on their phones, not a gaming device. One of the founders of Bioware lauded iPhone games when asked what he's been playing. "Every week it's like 'what's new?' It has become so easy to play them. Trying to play Scott Adam's Pirate Adventure on an Apple II with a tape drive, that was hard to do. It's very easy to play on the iPhone," Dr. Greg Zeschuk said at DICE.

Each device you throw into your bag before you head into the airport has to justify its own existence, and for a growing number of the people who play games and, more influentially, the people who make our games, portable gaming hardware simply isn't making the cut.