I'm not an MLIS student or graduate, so I haven't read as much about 2.0 as a lot of the other 23 Thingers have. Seems like it has its ups and downs. Finding better ways to get our resources to our patrons is a necessary change that we've already been experiencing for some time. I can imagine a time in the near future when our Askus Hotline grows into a larger, increasingly important entity, as more of our services become available remotely and more patrons seek our help outside of our library buildings. Sharing information, techniques and ideas is a great idea, and necessary if we are to keep up. At the same time, having too much information can be almost as problematic as having not enough, if it's not organized in a way that makes it findable. As long as it has a real structure that makes it useful, then it sounds great.
As for the idea of allowing the public to post comments, reviews, ideas, etc on library sites, it's fine to give people a forum to express their thoughts and opinions, but I don't know about its usefulness as a tool for shaping library procedures and services. Very often when I read the comments section of any article that is even remotely controversial (or sometimes not even), I usually feel dumber for having done so. (Of course, that may be simply a testament to the sorts of sites I frequent.) Yes, we should listen to public opinion and cater our services to our patrons, but again, the effectiveness of this will depend on the structure its given.