Powell's introduction looks splendid. It is beautifully illustrated, with well chosen colour pictures from Christian art across the centuries. And the layout is splendid, with the text constantly broken up with nice little boxes and sidebars, bulletpoints and charts. It is very easy to navigate, rightly boasting that it is the kind of textbook you can dip into at any point. The discussion is crystal clear, easy to read and usually fair and accurate.
My guess is that it will be a direct rival to Bart Ehrman's Historical Introduction, now in its fourth edition, and now, just in the nick of time, with similar lavish illustrations. It will be a while before I can get a feel for whether Powell could do the unthinkable and replace Ehrman as the first-stop introduction, not around here in the heart of the Triangle, of course, but in places further afield.
One of the values of the new book is a website called Introducing the New Testament, a companion site that features lots of extra hand-out style student resources.