My guess was correct, which I realize isn't saying much. Still, I was surprised this morning to learn that both Half-Life 2 and Portal are already available for Nvidia's game-controller-plus-Tegra-and-screen thingy, otherwise known as Shield.
Half-Life 2 will set you back $9.99 in the Play store, and I'm not sure what to do now. The Shield's ability to stream games from a remote PC works awfully well, and I already own HL2 on Steam. The options, there are so many. I suppose having the Shield version would be nice for traveling or the like.
Nvidia cites these game releases as evidence that it's working to build a strong stable of games for its portable console. I've not yet tried HL2, but Portal translates surprisingly well to the Shield, with well-balanced controls and smooth, PC-replica graphics.