Giants.
This is the first book without a single giant, possibly Donaldson's greatest creation in terms of an entire race. In the previous books, no matter how low the self-asteem and despair of Covenent became, it was relieved by an optimistic and pro-active giant.*
Stone and Sea, I miss them.

*(OK, they didn't REALLY appear in 'The Illearth War'; Keelsetter lasted all of three or four pages...and Kinslaughterer, well, was a Raver...but this shows my point as I find Illearth to be the darkest of the first Chronicles.)