By Richard Martin

As expected, Facebook unveiled its new e-mail service, dubbed Project Titan” internally, in a press event today preceding the Web 2.0 conference in San Francisco. The new version of Facebook Messages will attempt to erase the distinction between e-mail, texts and other forms of instant digital communication.

You decide how you want to talk to your friends: via SMS, chat, e-mail or Messages,” wrote Joel Seligstein on the official Facebook blog. They will receive your message through whatever medium or device is convenient for them, and you can both have a conversation in real time.”

The question now becomes, Can Facemail” really take on Gmail, and help the worlds largest social-networking site taken on the worlds largest search engine provider?

The early answer is Probably not.” While even a 10 percent slice of Facebooks 500 million users would be a healthy e-mail user base (50 million, in case your calculators not handy), Facebook still has several hurdles to overcome before it can establish a one-stop e-mail service that grown-ups use for both business and pleasure.

The first hurdle is simple perception: While it has plenty of older users, Facebook is still seen by many as a playground for the high-school and college demographic, and Facemail will probably be perceived as an extension of that. This was evident early on in CEO Mark Zuckerbergs presentation introducing what he called a modern messaging system.” As quoted on TechCrunch (which had the early reports of the Facemail announcement), Zuckerberg mentioned that, in talking to groups of high-schoolers recently it became clear that they find e-mail too formal.”

To overcome that formality, Facebook has combined a social inbox” with seamless messaging across platforms and conversation histories.”

Thats great, but while plenty of 20-somethings have migrated to texting for their primary form of digital communication, a vast majority of adults still rely primarily on e-mail for their daily personal and business communications. And for a company that has been dogged repeatedly by charges of privacy invasion, creating a social inbox” could be a tactical error.

In a Tweet on the Washington Post feed, a commenter summed up the hesitation many will feel about moving to Facebook for their primary communication: I’m definitely not using a e-mail service by Facebook  it’s not professional & I can’t rely on it to be safe/very private!”

The second challenge is matching the powerful integration of Gmail with calendars, chat, text, documents, voice calls and video. Obviously with seamless messaging, Facebook is attempting something similar; but, for the moment, it simply cant match the level of online applications that Google offers. Sharing photos with your dozens of friends is one thing; full integration of your e-mail with virtually all of your communication and collaboration tools, including your Android smartphone, is another.

Theres no question, though, that Facebook automatically becomes a significant player on the e-mail and messaging front. As Reuters reported, this weeks Web 2.0 will see the two Web giants lay out their competing visions to create a new generation of Web services.” Users will benefit.