regulation won't change anything , bitcoin gambling sites will remain struggle to get a new player.
you know why? they are still have a lot of fear they won't get paid. but yes at least with this regulation rumour some people will try to play here and see the result whether are they feel comfortable enough to stay or just ignore it.
I feel gambling already had a huge boost with bitcoin's existence. There are so much bitcoin gambling sites that have been able to build some reputations for themselves. However, like you said, the regulation would make some impact as people will be more and rest assured of getting their pay.
This more importantly, will cause more adoption for bitcoin as we see more gamblers stepping into the bitcoin world and most of the strong gambling site making a huge load for themselves.