During a Wednesday live chat over on the official PlayStation site, ModNation Racers: Road Trip producer Vernon Mollette II confirmed that the game will be shipping without support for head-to-head online multiplayer.
You'll still be able to race against your friends face-to-face over an ad-hoc connection, but if you're as misanthropic as we are, you're out of luck. Mollette says the team decided to focus on an more robust set of "asychronous" online multiplayer features. In other words, you'll have to settle for ghosts and leaderboards when you take your Vita online.
It's an interesting omission, because, as one fan pointed out, the PSP version of ModNation Racers from way back in 2010 supported online multiplayer for up to six racers at once. This step back seems odd, and it's hard not to wonder if they had to throw the feature on the chopping block so Road Trip could make it out in time for the Vita's Western launch.