There are many excellent posts regarding Web 1.0, 2.0 and recently Web 3.0. For example, Does the Semantic Web = Web 3.0? and Web 2.0 isn’t dead, but Web 3.0 is bubbling up.
Problem with web versioning is people are forgetting web is software as a service(SaaS), rather than traditional software. One of the biggest differences between SaaS and traditional software is the invisibility of versioning.