The hottest mobile Internet properties in Asia right now are messaging apps that are beefed up with social networking features. China’s Weixin. Korea’s KakaoTalk. Japan’s Line.

Increasingly, I’m coming to believe that the West will copy these apps, all of which cover multiple communications functions: instant chat, voice messaging, photo-sharing, connected address books, and timelines, to name a few. These apps, built with a mobile world in mind, just make sense. Facebook and Google have to build backwards to adapt to the age of mobile. These Asian messaging services, on the other hand, were born into it. They own it.

As I suggested the other day, Facebook on mobile might ultimately look a lot more like Weixin than anything else. It’s hard to make sense of the idea that consumers would willingly fragment their social presences across so many services. Why maintain separate accounts on Facebook, Path, Instagram, Google+, Group.Me, Pair, and WhatsApp when you can get all those services intelligently integrated into one product?

In China and Korea, the all-in-one model has already proven wildly successful. That’s at least in part because those countries didn’t live through the early frontier stages of the iOS app ecosystem, in which pure-play verticals have been allowed to flourish while Facebook and Google have struggled to decide exactly what they’re going to do on mobile.

Weixin, made by the dominant Tencent, has accrued more than 100 million users in just a year of existence. It’s only getting started. Just last week, news broke of Weixin adding Skype-like live voice and video to its next update. KakaoTalk, in which Tencent invested $61 million for a 14 percent stake, already has those functions. It has 50 million users in Korea.

Those are huge numbers, but they start to look even more significant when placed alongside Facebook’s penetration in those markets. In China, of course, that penetration is close to nil, because the social network is blocked. In Korea, where Facebook has only recently started to make in-roads, Facebook has just a tick over 7 million users. Another plus? KakaoTalk already has a strong monetization model.

Facebook must be concerned by these developments. In many developing markets, more people access the Internet through their mobile devices than via a PC. In the US, Internet users already spend more time in mobile apps than they do on desktop Internet. For now, a lot of those users are spending time on Facebook, but at least in Asia their social networks are increasingly shifting to the likes of Weixin and KakaoTalk. And those networks, tied closely to their address books, are likely to be tighter and more useful. If all your best friends are already on your favorite messaging platform, the advantage of heading over to bloated, unfriendly-to-mobile Facebook seems less and less clear.

Asia, and Korea in particular, has a history of showing the way with the Internet. Korean social network Cyworld preceded Friendster and proved the value of virtual items. Nexon and Tencent have been making bank from micropayments for years before Zynga discovered them. Now that a new ecosystem is evolving, it would be foolish to dismiss the potential of these countries to once again lead the world.