Crossbuy means that the disparate versions of first-party titles like PlayStation All-Stars: Battle Royale, Sly Cooper and Ratchet and Clank QForce, which will be all but identical on PS3 and PS Vita, will be sold together. So you buy the game once, and you get both versions.
This is fantastic news, and it's great that Sony's doing what's best for consumers and not necessarily best for the bottom line—though getting both versions of a game for the price of one is certainly another incentive to go out and buy it (and a Vita, for that matter).
And Crossbuy will reportedly factor "heavily" in the future of Sony's PlayStation platforms.
Now will you buy a Vita? Tell us in the comments or on Twitter.