The publishing process became simpler because many companies discovered that free content is a lucrative business and provided systems to make it easy. As you can see, the revolution of Blogging is not a technical revolution just a marketing phenomena.
The same process happens now to the new buzz word, "Web2.0". Many companies now understand that it is much cheaper to let someone else do your programming and marketing and open their API's. Other programmers improve the sites services at no cost and provide additional traffic at almost no cost. Other than referral fees in some cases, the process is totally free for the companies.
Imagine Google trying to reach an agreement with e-Bay regarding the use of craigslist's database on Google maps. This process would have probably required months of negotiating and hundreds of lawyers. It is much simpler to open your API , let someone else do the work , and call it synergy, mash-ups or Web2.0.