ModNation Racers will be out and ready to buy with the console, and all of the tracks and vehicles (that's all of them) currently available on the PS3 and PSP will be available to download and play right away. That's a ton of content, and just picking up ModNation Racers gets you access to all of it, a pretty clever way to fill out what might be a pretty sparse launch library for the PS Vita.
That in itself might be enough to sell the game -- a racing title is hard to mess up even on a brand new handheld, and of course this one plays just as well as all of the other versions. But no, Sony's taken the ambitious step of including the ModNation Racers editor in the mix, allowing you to make use of all of the PS Vita's various bells and whistles while building up tracks.
And for the most part, it works, both as an actual track editor, and as a showcase for interacting with the Vita's touchscreens. There are a few hiccups (pressing on the rear touchscreen to make mountains is weird), but it all works out quite well.