
Apparently either Sony forgot to plan the data prices with AT&T for the 3G model or AT&T completely forgot all about the Vita for the US release because as of right now there is no special discount plan for the Vita.
Instead it will be using a similar data plan done by the iPhone and other mobile devices.
250MB of data - $14.99/month
2GB of data - $25/month
The 3G model requires a plan in order to play online games due to just the 3G model being subsidized which ends up being about $300 per year. In comparison an Xbox Live Gold account is only $60 per year ($5 per month).
http://www.gamezone.com/news/ps-vita...the-whole-time