And the killing of tons and tons of characters also kinda stays that way, unfortunately - every book has the same concept of a slow build-up to a massive climax, in many cases with an impressive body count.

As for new characters and storylines, book four is a direct sequel to book two; book five starts from zero (and this time really from zero, there is exactly one character in the book that you've met already, and for him the story is a prequel), all the ones after that follow previous books (six picks up again where four left off, seven where five left off, eight kinda follows three, not sure about the last two).

I hope you enjoy Memories of Ice, most people feel that it's the best book and high point of the series. Which is obviously not a good sign in a ten books series... not that everything after that is bad - five in particular is good as well - but it's still somewhat disappointing.