Blogging has had a low persistence rate for years. I'd like to think that the best bloggers are sticking around...but I've always been a Candide at heart.
Rowse's response to the decline of blogging wrote following:-
Blogging is not dead - it’s evolving.
You should be evolving too (read Blogs are Out of Beta, But Bloggers Should always be in Beta)
Keep being useful, keep solving problems and keep meeting needs - whatever the medium this is key.
Keep producing content - people continue to search the web for content in huge numbers. It’s not all about networking and bookmarking - whether it be text, video or audio - keep producing content.
Experiment with different mediums - to the best of your ability keep abreast of the ‘new’ mediums that are emerging.
Build a ‘Home Base’ - many people flit from one medium to another and end up with nothing of their own (read more on the Home Bases and Outposts that I use).
Build a Brand - the mediums are tools. They’ll come and go in time - the key is to build something that lasts beyond them.
Don’t be Precious about your ‘Blog’ and be open to change - there’s no one ‘right’ way to blog. Blogs can have comments or not have comments, have full RSS feeds or partial ones, look like a traditional blog or act and look more like a lifestream or portal. The key is to know what you want to achieve and let that shape what you do with your blog.
Don’t abandon your blog too quickly - your primary efforts may move into a different medium but blogs can be an important part of the mix of what you do online. Don’t abandon your blog - build upon it, let it evolve, leverage what you’ve already built and use it where appropriate in the mix of what you do.
I think its a pretty good article about how blogging is a great tool. I'm hoping to soon add to Darren's list in the near future on why I blog.