There will be 21 000 000 bitcoins.
If 1BTC would be 1 000 000 mln dollars then I ask
is there 21 000 000 * 1 000 000 == 21 000 000 000 000 dollars in the world? (21 trillion dollars)
You don't really need 21T$ for that. 1T$ is enough.
Anyway, dollar-hyperinflation is around the corner. We had hyperinflation of major currencies in the past, and will have it again.
1M$ for BTC might be reached easily this way. Of course this won't make you super-rich :-D
When it will happen? Right when China and other countries stop selling goods and resources to US for fiat paper.
Maybe next year. Maybe 2015.