Will never happen. Can't see it staying higher that say 300/400 for any length of time. if it did it would price the normal person out of bitcoin as a currency. It would be bad for 95% of users if it were to go that high..
Anything can happen in bitcoin and it will also happen, but no one knows that when will it happen, But I am sure when all of the bitcoins are mined and every person of the world adopt and use bitcoin then I think at that time that amount will be reached.