As for Spider-Man: Turn Off the Dark...
I think the whole pop culture aspect of the Spider-Man tradition, myth and franchise, along with Bono and The Edge's involvement in the show in a way trumps Julie Taymor's involvement. There really was such a built in audience as soon as the project was announced years ago. Ms. Taymor was obviously(?) brought on to add some theatrical legitimacy to the proceedings. Of course, all after the delays and the injuries, Ms. Taymor has come under more scrutiny from the press and from those who already know her name, her work. Sadly(?), I'm betting a good majority of the "audience" - past, present and future - doesn't really care who or what Julie Taymor is. They just want to see Spider-Man come to life on stage, and/or they want to hear the latest works by U2. -How many moviegoers really go to see a film just because of who directed it?
Yes, the Press and the Reviewers can, do and will have an impact on the show in some form or another. However, I also believe that the Spider-Man fans, the U2 fans and their friends will have more of an influence simply through their word-of-mouth, Facebook status updates and Twitter feeds.