"Perhaps one day not long from now, everything on the Web will be a mere extension of Facebook." - a very optimistic view of the growth of FB , to put it mildly.
Sure. But remember that there was a time in recent memory where the notion that AOL would be a mere extension of the web was a very optimistic thought as well, or that some young upstart would knock AltaVista from king-of-the-hill in Search.
"Prediction is very difficult, especially about the future."
+1, may be something new come and take it! It's just a luck for facebook that no other new startup screw them (Twitter is good, but too limited comparing to Facebook)
It is entirely possible that the incentives are aligned in such a configuration - where to maintain that position, facebook needs to be better for all parties involved.
Think of this with respect to google. Their business grows linearly with search usage, so their incentives are to create faster and more open access to the internet. Don't believe that "don't be evil" bullshit. They act the way they do because it makes them a great deal of money. AND, it benefits pretty much everyone expect dinosaur incumbents.
Gordon Brown called this "sophisticated enlightenment" in a recent TED talk.. that is, aligning one's personal interests with what is good for those outside your immediate obligations.
I wouldn't be so quick to call it evil. It's about as good as it gets. True altruism doesn't sustain a business.