Mark Zuckerberg may claim it’s not an e-mail killer, but if Facebook users embrace the new Project Titan as their one-stop communication shop, Microsofts Windows Live/ Hotmail seems likely to be the first email provider to suffer.

A report by Roy Morgan Single Source shows over half of Windows Live/Hotmail users have a Facebook account, compared to roughly 16% of Bigpond and Yahoo email users and 20% of Gmail users.

Roy Morgan’s data chartered the rapid growth Facebook has experienced in visitors, increasing from 0.3% of the Australian population aged 14+ in December 2006 to 38% in the 12 months to June 2010. It is still growing, with 44% of the population in September 2010, an estimated 6.8 million Australians, visiting Facebook.

Given (Titan) proposed seamless integration of messaging types, there will be a few concerns at the largest email providers, such as Microsoft,” said Andrew Braun, Roy Morgan Research’s industry director of mobile, internet and technology.

“If 50% of Facebook users moved to Facebook for their email this would create a big hole for the other email providers.

“However, if we recall the ill-fate of Google Wave, which was at the time touted as the next ‘email killer,’ this new system may simply be a nice addition to Facebook’s artillery and not the death of email.

“It will be interesting to see how the take-up of Facebook’s new messaging platform impacts the use of email and these email sites.”