Indiana Jones in 1980 took four minutes with Dr. Jones at a chalkboard to set up for the audience what the macguffin was like, why it mattered, how they would search for and find it. Then it was a nonstop ride to try to achieve what he described, though there were many detours. This had the added benefit of allowing Jones to do something (like making a staff of Ra and putting it in the map room without really needing to explain much of it through awkward dialogue exposition.
Indiana Jones in 2008 doesn't bother setting anything up for the audience, and exposition is spit out, on the run, often in the middle of an action sequence, which is how many modern blockbusters are made. Imagine, if instead of an offhand comment about the Nezca practice of wrapping infants heads to mold the shapes of their skulls while they're searching the graveyard, he set up the Nezca the way he did the ark of the covenant, explaining that the crystall skull to the nezca was an equivalent holy object, that you could find it in such and such manner and legend said it would accomplish such and such. Suddenly you need a lot less of that incredibly awkward "we're going to explain a new detail of the mystery now" of the dialogue--which in my opinion is the most frustrating aspect of the film. the writer (Koepp) treats the macguffin as a mystery to be figured out/explained, and that misses the point entirely, mystical elements, be they shankara stones, Grails, Arks or the Force are naturally mysterious, we don't need to explain them ala midicholorians or interdimensionality.
But it is Indiana Jones and there is something incredibly appealing about him and many points of this film that make me like it more than any other film this year and many other points that just frustrate me with their awkwardness.
Going to the storage warehouse was a great set piece, survival of a nuclear blast not so much (as kitschy as it was to have those sets and recreating Atomic Cafe), the chase through the campus was for me one of the highest points of pure Indy of the entire film. Just absolutely awesome from beginning to end. Then the visit to Ox's cell seemed boring and a retread of the awesome library in Last Crusade, this is followed by the trip to a graveyard (how on earth did Indy know from some scribbles on the ground and how did he know which one and where it was?) which has some interesting action and then a great scene when they find the skull and, being an Indiana Jones movie, are recaptured. All sorts of interesting things go on, Marion shows up and then there's the extensive Jungle Chase to the temple.The Jungle Chase is where the movie really picks up, goes into absurd-ville fully (second favorite part of the movie was Tarzan), which actually make sense because they've already had him survive a nuclear bomb. And then finishes everything off in the temple (with a lackluster escape to boot). Performances, cinematography and direction are top notch, the script is weak but overall, it is Different, it is still Indiana Jones, but it is different.
there are more plot holes than all the other three films combined, though, the most glaring one being that Ox found the skull made it all the way to the temple, couldn't figure it out and returned with the skull all the way and returned it. This whole bit made no sense at all to me.
I'd probably give it a seven of ten, but it could very well end up making my end of year top ten list, despite such a low score, placing well above films I rate higher.

There's something about Indiana Jones that is still very compelling now as it was in the older films, and that kind of counterbalances the poroblems of the script.