I'll make a few comments, but try toleave them spoilerless so that aeque, poor dear who has not yet got the book, doesn't find out anything very important.
Firstly: a very good book, but in my personal opinion, one that has to be read more than once - preferably just after reading the first three books again. Because SR is just packed with little self-referencial nods. There are little things, talking about what has already happened, subtle things that you will barely pick up on, some unexpected things, and one of two that make the plot. And no, I will not tell anyone what they are.
As usual, the book is brilliantly insane - how could it not be with a guild of stalkers, cloned Shakespeares, foul-mouthed saints, a political TV show called "Evade the Question Time," and a croquet world cup that may cause an armaggedeon. (sp?)
As it is set back in the Outland,the main characters are those from the earlier Next books, but there are a few book characters showing up - the major one being Hamlet (though I adored Zhark - he is hilarious!) Also, there a few fascinating references that Thursday makes, wondering if life really is a book, which is fascinatingly ironic.
Also, just after you think the story has been wrapped up, there is a huge surprise that I promise no one will ever see coming.
*Sigh.* Wonderful, wonderful book.
Oh, and in other news, during my little shopping expedition yesterday, I also managed to buy a pair of The World's Cutest Shoes Ever. Unfortunately, now I am basically broke. At least I only have a week of school left!