I do not think Kaladin, Dalinar, Shallan, or Szeth will be dying any time soon. My evidence is the document on the back of the hardcover, which points out all four of them, the "four whom we watch". I don't have it on hand now, but I believe it indicates that one of them will be a savior and another a bringer of doom. I doubt that anyone will be dying before we have sufficient character development.
Maybe we will have a WoA-type ending to book 5, someone releases something bad (probably Odium) and that one is the bad one. Then they would die in the process of that. A release like that might be taking too much from Mistborn, though. That's sort of how I see the two 5-book arcs being separated: some not-yet-known issue will be resolved in book 5, but in the process something terrible happens to set up for the second cycle (release of Odium, return of Voidbringers, etc). Then we will all be rabid for more books, and Brandon will laugh and give us the second Mistborn trilogy instead. That trilogy will be great, but while we're happy with that, we will be theorizing like crazy over what will happen in the second Stormlight cycle.
Adolin is going to die at some point. He has the perfect place in the story: not too important on his own, only significant relative to Dalinar. Plus, it would be a great set-up for placing Renarin in a state of significance, which I believe will happen over the series.
Elhokar's death would be very interesting to see, as he has no heir. I don't know who would succeed him, probably Dalinar or one of his sons. I would love to see a succession conflict concurrent with the Desolation.
I feel like Bridge Four is going to get slaughtered at some point and send Kaladin on a rampage.
Just a point, I don't see people becoming Shards happening in this series; it would be too close to Mistborn, as much as I would love to see it.