There maybe a chance to use bitcoin for online gambling but still this depends upon the gambling organizer. But if ever the gambling site is on bitcoin this is a big possibility. Some online gambling might still use other currencies for their own purposes..
I hope you do realize that Bitcoin is
already being used for online gambling. For instance, take a look at this section. There are a lot of people gambling with their Bitcoin on online casino or gambling website.
Yes, Bitcoin is already being used for online gambling, but really what percentage of gambling sites are using Bitcoin now? I have never seen such statistics and I can only guess that the number is around 20% maybe, but it's interesting to know the real number though.