I don't think "mega-blogging" is actually a thing, I just made it up to make the title sound more dramatic. But if mega-blogging were a thing, you would do it with WordPress. Micro-blogging is a thing, ash a lot of people do it with Twitter.
New forms of social media, including micro-blogging, are complementary to blogging.
It's not really a "versus," it's an "and."
Blogging and micro-blogging can co-exist.