Being a big fan of DaizenshuuEX myself and having heard about it from over there, I do want to clarify a bit. I haven't checked the forum thread, but based on the podcast, a lot of what you've said is speculation. If more confirmed details have come out since then, then I apologize. The picture is going to be extended to 16:9, but it hasn't been confirmed that they're redrawing the backgrounds. While this is the most likely route, it doesn't necessarily mean it's true (but I will say that I agree that it's probably the case). As far as I know, FUNimation has said nothing about this, so there is no precedence other than fan wishing that this will ever see the light of day in America. Not saying it won't, but there hasn't been any official word. To clarify for those who don't know, Return of Son Goku and Friends isn't a movie, per se. It's not a movie like the other official movies with theatrical releases made as an extension to the TV show. This was an animated special promoting the anniversary of Jump, the publication that originally presented the manga. But, yes, it was certainly great! ^_^ And as a minor nitpick, Hirotaka Suzuoki isn't the only seiyuu who has passed on since the show ended. Jheese's voice actor died a few years ago, and you can't forget that Kohei Miyauchi (Kamesennin) died before the show even originally ended. So there are going to be more replacements than just for Tenshinhan.
As for the premise... I'm mostly apathetic about it. I don't really care about "refreshing" DBZ. And I really don't see the need to re-record the dialogue. It doesn't bother me they're doing it, as long as it's an alternative to the real DBZ, but I just don't see the point. Granted, it's a better idea than the live-action movie, but that's not necessarily saying much... The only thing about it that interests me is the length, trimming it down to a third of its episode count. That leads me to assume that they're removing the filler. That piques my curiosity. While there is some filler I enjoy, it would be nice to see the show more accurately portray the manga and also have a version where people can't complain it drags on for too long. So we'll just have to see how it goes! Thanks for posting this over here.