Blog was been here for since 1997 and it will continue to be in existence in the foreseeable future. In fact, some of the authoritative blogs (like Mashable, TechCrunch etc.) have over-shadowed the mainstream media for many years.
So, can you imagine one day if all the blogs gone holidays and MIA (Missing-In-Action)? I can't either.
In fact, there is a whole Blogconomy currently brewing "silently" in the online space and many of the professional bloggers are living out of it, comfortably. Recently, Ignite Spot produced a brilliant infographic that will answer all your doubts and queries about Blogconomy.