score:8
It is getting to be celebrated more and more. This is a direct effect of the appreciation of Hollywood movies and the creative usage of that appreciation by shops. So yes you would see more and more advertis*m*nt trying to convince people to celebrate Halloween, since it means top dollar in terms of turnover.
You might be invited to Halloween parties and then as a native halloween celabrator your way of how to celebrate Halloween would be appreciated as model for future celebrations.
In terms of the general public, it is not a big thing.