Is this important?

I ask that in all seriousness.

What will happen if Facebook buys Whatsapp?

The CIA/FBI will say a big thank you, and use it to spy on both American citizens and foreign nationals, as well as global citizens. If they aren't already; I'm sure they are where they can.

One world communication sounds like a dream, until you're the enemy.

Facebook bought WhatsApp. Good call. 

Fragmentation is fine but international texting has GOT to come down in price.

So much more expensive than email or even Skype.

 Only for Americans.

Essentially WhatsApp became huge last year. But the ecosystem is still fragmented.