According to a post by a post by a Virgin Mobile employee on the company's Facebook page, Virgin will be getting off-network roaming effective July 1st. In response to questions, the employee said that the roaming would apply to all Virgin Mobile devices and that he didn't know if there would be an extra charge for roaming.
Depending on which operators Virgin will roam on and the cost, if any, this could be a huge win for Virgin customers. Currently Virgin only works on Sprint's native network coverage which is mostly limited to cities, larger towns and along major highways. Competing prepaid services from the other three national carriers have much larger coverage footprints thanks to T-Mobile having long offered voice-only prepaid roaming and AT&T and Verizon having much larger native networks.
The Facebook response was prompted by a question about a section in the Virgin Mobile Terms of Services regarding roaming. Boost Mobile's Terms or Service have a similar reference to roaming, so it seems possible that Boost CDMA will get roaming at the same time as Virgin.
Update 6-Jun-2012: It now looks like Virgin Mobile roaming is not going to happen. Virgin Mobile has updated their Facebook page with the following:
Hi everyone. I need to clarify comments about roaming on Virgin Mobile. Roaming is not available. We did recently update our terms and conditions (effective 7/1/12) in order to make our language more consistent with Sprint’s. There is a new reference to roaming, but we have no plans to add roaming at this time. For information on whether roaming applies, see your service plan details. Our sincere apologies. ^Justin CVia: Howard Forums