I believe the hope here is not that it will bring forward some new revelation, but that it will simply get the general public excited about science again.
The original Cosmos series helped get a lot of the public talking about science, and probably grew some careers out of the kids that watched it as well. Whether Tyson and the rest of the new Cosmos staff will be able to do this remains to be seen, but I think the primary goal is not necessarily to give new insight into the mysteries of the universe, but to make thinking about these questions interesting again to the general public.
In today's television world of History being taught by Pawn Stars, and The Learning Channel showing us insights of child beauty pageants, reality shows are now the bread and butter for almost every network. It has seriously diluted the education that is occurring from television (and let's be honest, whether it should be or not, there is no escape that a lot of people do substitute television watching for actual learning). While PBS and a few other stray networks help a bit, this new series of Cosmos offers some hope. If NatGeo was the only one doing it, it would gain some attention, but the fact that a major over-the-air network like Fox (especially with its reputation) is teaming up with this is encouraging.
If the new Cosmos can actually succeed, not necessarily in explaining complex scientific theories about our world and the universe, but if it can succeed in what the original Cosmos did in just getting everyday people excited in science again, it would do a lot of long term good for this country. Perhaps, just perhaps, a few other networks could follow suit and knock out one or two hours a week of their reality programs to put more science into their programming. Perhaps it can get more people, especially young people, into looking at science as a viable career option instead of trying to figure out how to get their 15 mins of fame on another reality show. Lofty dreams to be sure, but we have to start somewhere, and hopefully this new series will either help be that spark to get others excited, or confirm once and for all that no one in this country really gives a damn about science and watch as our scientific knowledge plummets compared to the rest of the world.