So I'm claiming here that the Web we have today is incomplete. How comes? Imagine you have a wonderful programming language which is object-oriented, nicely to read, produces beautiful documentation, etc. but does not support, say, I/O operations. Would you be able to use it? At least for a number of real-world problems this programming language would not be regarded to be of practical value, but rather to be incomplete.
This is basically the point I'm trying to make here regarding the Web x.0, nowadays. Quite a long time the Web of Data (The-Thing-Formerly-Known-As-The-Semantic-Web) has been viewed as a kind of addition to the Web of Documents, that is the Web intended to be consumed primarily by humans. Now, take a second and think of our wonderful programming language, described earlier (this is the current Web).
Indeed, the Web of Data is not an extension of the Web, but rather the equation
There is a bunch of applications that is close to impossible to realise without an explicit representation of the data out there: starting with portability of user data between social media platforms over smart tagging to data integration.
So, the good news is that the Web is not incomplete anymore. The challenge, however, remains to understand this and start using it properly.