London-based Disruptive Analysis this week published a report, "VoIPo3G Business Models," stating that mobile VoIP is rapidly going to eclipse VoIP over Wi-Fi. The expectation is that "VoIPo3G" users will reach 250 million by the end of the 2012.

And the research firm says it'll be a win/win for everyone. "Carriers will become increasingly attracted to VoIPo3G because it will enable them to fit more phone calls into their scarce spectrum allocations, reduce operating expenses by combining fixed and mobile core networks, and launch new services like push-to-talk and voice-integrated 'mashups,'" according to a statement.

Makes sense to me - but ZDNet's Russell Shaw isn't buying it. "Entrenched cell carriers will go to all marketing, regulatory, legal, lobbying and statutory costs to protect the current business models they believe are necessary to protect their investments in networks as they are now," he warns.

More here from Computerworld ... more here from Telappliant ... more here from TMCnet ... and the press release is here.