Or... you can spend that same amount on a device that does gaming in 3D! That absolutely pales in comparison on everything else, but it's okay since 3D gaming battery life is the obvious tantamount to a platform's gaming worth /s/
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Not everyone wants nor needs an extra convergence device. If someone wants a system for portable gaming then the 3DS is clearly the superior choice. Underestimate the importance of battery life for a portable gaming machine at your peril, doing just that was the ultimate downfall of Atari, SEGA, Nokia and Sony. There's more to it than just battery life and stereo 3D though (though to downplay the importance of either of those is simply ludicrous) and to pretend otherwise is to be deliberately obtuse. The 3DS has buttons, a dpad and an analog stick, now call me a traditionalist but having access to them tends to be important for all but the most casual of gaming genres. Touch screen and motion controls can be nice but the difference with the 3DS is that it offers those options in addition to traditional controls so that everything controls fantastically on it, you don't have to resort to gimped gameplay or completely rework the game in order for a game to play well on the device.
The iOS has proven that it simply can't support games that are price at $10 or above. Now, this might change but it is the reality of that market right now and has been for quite a while now, and that has huge consequences for the sort of support the platform gets. You'll never be able to play a full mainline Dragon Quest, Resident Evil, Kingdom Hearts, Pokemon or MGS title on your iPod, the realities of the marketplace completely prevent it.
Oh, and there's the small matter of Nintendo software. Having Pokemon, Super Mario Bros, Nintendogs, Zelda and Mario Kart exclusive to Nintendo handhelds is kind of a big deal.
For someone who wants a device to play games on the go all of this stuff is a big deal. Sure the iPod may offer a better browsing experience but then you need to be within range of a wifi hotspot to utilise that functionality which severely limits the usefulness of such functionality.
P.S. Its not going to be $300 in the US, this announcement just guaranteed that. $250 looks the most likely at this point (which I admit is overpriced for a dedicated gaming portable) but $200 could still be possible in the US if they ditch the SD card, charging cradle and 5 game pack in.