I just passed the new Security+ test with a score of 871. My entire preparation consisted of reading "Security+ Get Certified Get Ahead" and doing the included review questions. I saw absolutely nothing on the test that wasn't thoroughly covered in the book. It is straightforward, easy to read, and does an excellent job of explaining some complex topics. I see no reason to invest in any other prep materials. The plan is pretty simple, buy this book, read it, do the practice questions, pass the test.
Update as of 2/17/2012: I just finished instructing a 5 day Security+ Boot Camp using this book as the only text for the class. We spent 4 days covering the material, reviewed for 2 hours Friday morning then the students took the test. All 13 passed and are now Security+ certified. Note that although some in the class had some cyber security experience most were new to the field and none were familiar with all of the topics.