Polish federation is ready to organize it, but there is a lot of task to discuss. Personally I think it won't happen in the next year, but everything is possible.
Well, I think that full stadium is expected. So it's about 60000 people. It's important to say that National Stadium is situated in capital city, Warsaw, where there is no volleyball except Politechnika.
I don't know first how FIVB will let them(this is the least problem, I guess Poland has got some great connections in FIVB ), but generally I don't know how will things turn up. It would be extremely difficult to follow the game from the highest and farthest seats without watching only in the screen.
But still, if this thing works, I guess the revenue from single game attendance will be tripled! And this is huge for Poland, cause I don't see any other country except Poland and Brazil who can fill more than 50 000 seats.
Anyway, this is kind of a "wild guess" by the Polish Federation. It would either be a huge success or end up in a disaster.