My wishes for an hypothetical "Indy 5" would be (in order of importance):
1) DON'T DO IT!!!
2) If you really can't help doing it, then DO IT AS A PREQUEL OR A RETCON.
A sequel would inevitably be a deathblow to the entire, already-agonizing saga. For A LOT of reasons.
3) no more Marion Ravenwood and, most importantly, NO MORE MUTT WILLIAMS.
Indiana Jones' franchise doesn't need to appeal to children and "stupid-films" fanboys.
4) Possibly a good ADVENTURE story. No more terribly unworthy sci-fi crossovers. If aliens are involved, maybe it's time to use 'em in a smart way (example: if the fourth movie had been inspired by "The Infernal Machine" instead that by the
horrible "Saucer Men From Mars" script, then it would have had all the qualities to be
a true masterpiece, on par with the previous three if not even superior. And in "The Infernal Machine" there are LOTS of aliens). Think about it.
5) To me, the right Indy girl for the fifties should be Sophia Hapgood.
6) The returning character, instead, should be "Mac" McHale. If so, Sallah or Short Round could have parts in the opening sequence. And I would also like to add to my wish list a possible cameo appearence of Willie Scott.
7) Finally... hundreds of thousands of bloodthirsty piranhas that make those stupid CGI ants turn pale!!!
On a side note... it's funny to notice how some of you guys have written far better stories then the "Kingdom of the Crystal Skull" one. Thumbs up to you.
Shame on David Koepp.