As neat as it would be to see, the most interesting thing about the press release is the many comparisons to Game of Thrones, especially the ones that claim the Amber was an inspiration for Westros. Now, I have yet to read any of the books and have only seen a little of the show, but I can definitely understand where such comparisons come from, given all that happens in Amber in these relatively short books.
When we left Corwin, he had just recovered his memories and declared his intentions to move against Eric, the brother who currently controls the throne of Amber. Indeed, Eric is about to throw himself a coronation, which makes it a perfect time for Corwin to hastily assemble a huge army of primitives from some shadow-reality or other (he does feel a twinge of guilt about this), lose 90% of them to the perils of the journey (implied to be caused by a weird power of Eric's), battle through the very gates of Amber itself . . . and be captured.
Yes, Zelazny completely subverts the expected triumph of our protagonist, letting Eric force him into participating in the coronation (Corwin crowns himself first, to no avail), burn his eyes out, and leave him to rot in the dungeons.
Happily for Corwin, the exact opposite happens. It takes four years, but his eyes grow back and, with the assistance of another prisoner, he escapes. And that's the end of the first book.
Now, that's a lot of ground to cover with the novel's page count, but Zelazny makes up for it with a relatively breezy style that neither dwells on the multidimensional military march (another reviewer I read recently but can no longer find compared that section to a series of military bulletins) nor revels in the eye-burning process - Eric commands it, Corwin curses at him, and then it's over and he's in the dungeon smoking smuggled cigarettes. It's a delicate balance, but Zelazny skillfully gives just enough detail for the reader to imagine the rest. His escape is a bit of a deus ex machina, but only a bit of one as most of the elements were set up beforehand.
With the basic premise settled, the second novel The Guns of Avalon start really setting up what I suspect are going to be major themes going forward. Corwin's immediate goal is to develop firearms that work in Amber (the physics are just different enough that regular gunpowder doesn't, another now-common conceit that I think Zelzany may have originated), for which he needs to visit a shadow-realm known as Avalon. Despite the name and a cameo appearance by Sir Lancelot, however, this is no Arthurian fantasy - in fact, Corwin himself was the ruler long before his amnesia-driven exile, and from the hints given he was a fairly despotic one.
After a great deal of subterfuge, combat, and journeying (including the fight with the dire Siamese depicted on the cover art), Corwin finds himself back in Amber with an army of fire-arm bearing troops . . . right in the middle of his family's battle against a Chaos invasion. Quickly deciding that his overthrow of Eric's regime can wait until reality is no longer threatened, he throws in with his family and winds up with the kingship anyway, when Eric is conveniently killed. Of course, that means that he's the one now in charge of defending against the Chaos invasion, a story arc set up with a very skillful revelation of a Chaos spy in the family who promptly escapes.
I'm skipping a lot here - Zelazny is very skillful at world-building by implication from a few remarks. For example, Sir Lancelot's appearance indicates that the shadow-realms of Amber include not only our world, but the various worlds of fiction and myth.
To bring this series to a belated conclusion, the first two Books of Amber showcase how Roger Zelazny used, and may have pioneered, many of the tropes used in sci-fi and fantasy works today. He did so using a sparse prose style that nonetheless paints a vast setting, writes gripping scenes of action and intrigue, and undergirds the whole with a subtle message of repentance and redemption for past misdeeds. Not for nothing, I think, is he known as one of the genre's Grandmasters.