If you read Fall of Reach (if you havent but plan to stop reading now because this is a spoiler) you would know that Sam dies before Reach. I doubt it will be him. If these are spartans from the novels it will probably be Fred, Will, and the ones youlisted (minus Sam). I dont think it will be them though. Im expecting Bungie to show us something completely new in the Halo universe.
It better be spartans, I find playing halo a more enjoyable experience as a super solider. Also, just because Sam died later into the book, why does that mean hes not a big part of the games story? Heck, the game could just be the story starting from the spartan training with the end being the final battle of Reach! Theres plenty of time for Sam to become a major part of the story line. Theres also a spartan I remember reading in the fall of Reach book who was supposed to be the combat expert and used a knife a lot. Anyways... at least bungie is finally starting to release more info about Reach and their progression so far.