I would recommend to try to contain your excitement as the Japanese blue ray releases take about half a year and before that, you will have a hard time finding even an undubbed version of it.
what's wrong with fansubs?
i welcome any new db/dbz content. i wonder what the movie will be about
Nothing at all, but I don't think you've understood the main problem here... which is based on my mistake of course as I accidentally wrote undubbed instead of unsubbed.
For series airing on tv, fansubs are no problem at all, as the material can simply be recorded, edited and more or less legally distributed over the internet.
In the case of movies, however, fansubbers don't have that opportunity. The movies that are released in theatres take way longer to be released on DVD/BluRay than in the western world (around half a year). Fansubbers would either require the original Japanese DVD (and usually those are released with pretty well done English subtitles in most cases) or a camrip of the movie and those are highly illegal quite hard to get your hands on most of the time, so barely any fansubber group will take it upon itself to take that risk.
Just take the K-On movie as an example. I wasn't able to find any version of it on the internet before the official DVD/BluRay release and I really did search for it thoroughly.