Prediction: Nintendo and Sony are going to switch places this gen handheld wise.

[Nintendoninja]

The OP is correct to emphasize the games, since that always determines the winner. However, I'm not sure what is meant by Westernized games.

If he means games made by western devs, then the 3DS will have both Scribblenauts Unlimited and a new Epic Mickey this holiday. Sure, they don't have the name recognition of Call of Duty or Assassin's Creed, but one is from a franchise that is a proven hit on handhelds and the other features a timeless mascot and inspiration from a beloved 16-bit game.

If he means games in the action genre favored by western devs, then I'll concede that the Vita has more of those, but I'm not sure that's an advantage. Sony introduced the Vita as the way to finally play console-style games on the go without first making sure that it's what people want. The Vita has no shortage of such games, some of them high-profile, yet not one of them has sold 1 million yet according to VGC. Historically, the most successful genres on handhelds are puzzle, platformer, and rpg. On handhelds, it's usually better to have a Prof. Layton or Paper Mario on your side than an Uncharted or Assassin's Creed.

Finally, let's not forget that there is already a 2D Mario and a Pokemon game available this year. Even a few months old and/or developed for an older platform, both have proven to be huge guns in Nintendo's arsenal, especially during holidays. Combine this with the fact that the Vita's known line-up for 2013 is made of smaller or untested IPs, I don't think Nintendo will have to worry too much.