Firstly, it's nice to see that here, in comparison to the US amazon site, there's only one person reviewing the book who hasn't read it and has given it a one star. I can well understand fans annoyance at having to wait for the next book but no one is forcing them to buy this book, it is not an integral part of the main series, nor has it claimed to be.
This is a prequel to the Wheel of Time series, now 10 books long. In Jordan's most recent interview (Jan 04) he states that he anticipates being able to finish in perhaps two books (he has been saying this since 1994 however, so be warned). While it has been advertised as an entry point to the series, I would not recommend it as such. Concepts are not sufficiently explained and to be honest the Eye of the World, the first book in the series, can work as a stand alone book. Try that before this.
The book comes in essentially two parts; the first concerns Moiraine and Siuan, two young women who feature later in the series. The story documents how they become fully-fledged Aes Sedai after many years of training and how they come to begin a search for the Dragon Reborn. This part of the book is great for fans in that we see a lot more of the White Tower than previously. We also see what could be deemed 'normal' AS training as opposed to that shown for Elayne, Egwene and Nynaeve in the main series. Jordan's writing style, in contrast to his more recent work, is concise yet retaining his trademarks to a sufficient degree to be interesting.
The second part of the novel is essentially the novella in Legends. If you've already read this, then the last 100 pages will simply be the same old material.
If your a fan and haven't got Legends, see this as simply more material. An enjoyable read even if it does not progress the series. As a non-fan, this could be a confusing novel that in the end stops before the real action begins.