I've just started this - hooray, the last one!
There's at least 5 projected in the series.I thought this too, till I finished the book Amazon (UK) list book 4 for Nov 2008.
On reading the book though I thought it went a little pear shaped, it had a little Jordanish feel to it, too many POV's brought the pace of the book to a snails pace.
Maybe my expectations were a little too high and I'm seeing problems that aren't there?
Would love too hear what the rest of you JVJ fans thought of it.
There are three books - The Book of Words Trilogy - that take place before A Cavern of Black Ice. This trilogy shows you much more of the world. Arguably they're not essential to read, but there are some characters shared between them and you appreciate the scope of the world much more by reading the prior trilogy first.