I hope the movie will be good as I was a massive Indiana Jones fan in the day, but 26 years on I am not sure how they are going to tie everything to the first movies.
Keep you eyes and ears opened. I believe they were really tight-lipped at first, but it seems that Spielberg is starting to leak out bits and pieces with time; perhaps to generate interest.
As you said, it HAS been a while since our last Indy outing...
The devoted / die hard I.J. fans will flock to see it, but IMO they'll need to attract more than just the "Indy-trekkies" for a blockbuster that's on par with the first three.
Then again, Star Trek never seems to have a problem. In fact, I just read that Nemoy is getting fitted now for his new Spock suit. No offense to ST fans, but F_CK'S SAKE!