I have a theory that one group of people has benefitted more from Web 2.0 than anyone else: Crafters. Thanks to blogs, crochet and knitting patterns are often only a google search away. Many of these patterns are completely free, and the range of patterns is ridulous. My favorite pattern so far is a peace sign as seen here: http://www.crochetspot.com/crochet-pattern-peace-sign-detailed/. Its easy to make, but I doubt anyone would think to put something like it in a published book. There are also all kinds of well-known character patterns available such as the angry birds, mario, and even complete tea sets.
The internet is also a great resource for beginners. Many bloggers are willing to post simple tips like stitches as well as reviews of necessary product brands. If you have any trouble, just comment and almost all craft bloggers will answer your questions.
The bloggers benefit as well. They sell finished products and sometimes patterns, and they get the benefit of being seen as an expert. Not everyone has the time to dedicate to getting themselves published or selling through retailers, but thanks to the Internet, they can still make some money with their hobby.
Who do you think has benefitted especially because of Web 2.0?