Part of me wants blogging tools to explicitly support cross posting (posting the same item in multiple blogs), and part of me is afraid of what will happen if they do. I hope they do it, carefully.
Of course, anyone can copy their entry from one blog and paste it into another. And many blogs support trackback, which can be made to do something similar. But what I want is for a person with multiple blogs to be able to write an entry and say "post this to this blog and this blog and this blog...simultaneously".
Why? Let's say you have a blog on blogging, one on internet technology, one for your family to read that's all about your life, and one that you just post everything to (I personally would never read the smorgashboard blog, but some people like to make them). One day, you post something about your own blogging experience. It belongs on all four blogs. But it's the same on each one. Depending on the mix of blogs you maintain, you may run into this type of situation often. A little help from the tools in getting things posted quickly would be nice.
Another reason goes back to the fact that it's the same in each blog. If each blog has a newsfeed and they all use the same permalink, guid, or whatever for the item, then aggregators will be able to tell immediately that it's a duplicate item.
Why does this idea scare me? If poorly implemented, it could allow blog spammers to cross post advertisements to many blogs at a time. Of course, they'll create tools to do that anyway, so maybe the question is moot. Blogging tools should only explicitly support cross posting at the top level--not in responses. And as long as only authorized individuals can post at the top level, there's no problem.
The solution sounds simple enough. So am I really afraid that spammers will take advantage? No. I just said that to make the news more sensational.