Walt Mossberg believes (like many) that the iPad is “a very good ereader.” He reviews reading apps from Apple, Amazon and BN/Nook and finds things to like–and dislike–about each. The hidden “news” is his finding that the iBookstore is up to 130,000 titles. From his modest price tests, he doesn’t seem to understand the books from the five big agency-model publishers will always be the same, but books from other publishers can vary.WSJ