Some people will prefer it - and some wont. It is only a "good idea" if it achieves the goal you seek by doing that.
If the article is very long ,that's not a bad idea.If you do so,you blog will take less time to load,you'll get more pv's, higher alexa ranking.Sounds cool..
I think it depends on the type of blog as well. For instance, one with news or product reviews could go with a summary on the front page. For others, a snippet of content works well.