I've seen Borders/Waldenbooks running the buy-3-get-1-free sale many times in the past, so if it's a bubble burst, it's an ongoing one. (The market is overflooded, certainly, but I hope that the quality series that are getting published help make up for it some.)

As to Death Note, it depends on how adorable you find L. :D There are a couple of detective-y characters later who are popular, though I haven't gotten to them yet, and there's a prominent female character I like who I hear gets annoying later. But nobody's a shining pillar of justice and kindness and lovableness.