Okay, back to my examination of the upcoming sets, and MOCs on the same themes. Helm's Deep is probably the most MOC'd thing in all of Tolkien (aside from someone simply pulling out their Majisto and saying "Gandalf!"). There's no way I could hope to put them all in this post, but here are a bunch of them. Technically these are all of the Hornburg and the Deeping Wall, not so much of the canyon behind them.
The Deathly Halliwell:
Micro versions by YU,
and Joshua Nichols:
Patriotic (US) versions in red (by RockSokka),
white (by Maartinio Wrigglypuffdoodle),
and blue (by Richard).
NIK444 focuses on the wall prior to it's being breached.
Popcorn focuses on the breach in the wall.
As does Jackson Williams:
TMM focuses on the Hornburg.
Last of all, here is mine. If you follow the link, it's the whole story illustrated.