I got into one however it was extemly glitchy, I was playing as PaRappa and this other guy was Sweet Tooth and as it turns out there were two other people in there but, we couldn't see them. Also the guy i was fighting just became invicible all of a sudden. I hope this gets fixed soon.
The closest I got to getting in on a match was hearing someone's voice at the "connecting" screen. After that I haven't played a match yet after trying for 15 mins now.
Btw anyone playing on their Vita when you first get it the Mic is automatically turned on. You might want to check if it's on when your playing because I didn't notice until someone talked back to me during the second beta run. Just to let anyone know who doesn't. It suprised the heck out of me to find out lol.