Certainly it could be depending upon its acceptance worldwide firstly and secondly if country allows the gambling as legal for that matter. So bitcoin could be future of online gambling but still need wait for a long time to see many gambling site will accept bitcoin as a one of a payment.
Definitely bitcoin brings the great security regarding payment issues, it take some time to go to mainstream to become the popular cryptocurrency surely bitcoin is future of online gambling, in recent surveys showing this how bright future online gambling have with bitcoin.