There are, *lots* of characters. But personally I feel thats what gives his books strength. I wouldn't say it suffers from the Jordan disease where you had 10 characters with similars names and 50 aes sedai that you couldn't give a shit if they lived or died. With Erikson's characters all of them feel flushed out, and you *feel* for all of them. I love R.R Martin's song of fire and ice, but other than Ned, John (and in the last book, Jamie) I really don't care about any of the characters.
Anyway, while Erikson does keep adding new characters, he tends to focus entire books of them and then they intertwine with the main plot, personally I love the style in which he does it.