As you may know, Google's Matt Cutts often posts videos on the company's Webmaster Help YouTube channel, answering user questions. He linked to one today about duplicate content concerns and having blog posts on your home page.
The question was, "Hi, I'm noticing more people are using the API for their blog to pull the latest X posts up to the front page of their website. This gives a refreshing feel to the home page, but is this considered duplicate?"
Cutts responded by saying, "If you do something like this, my main advice would be not to put the entire blog post on the home page, but for example, if you have a paragraph - you know, something that's sort of teaser - and then a link to the actual location of your article, that's a pretty good way to do it."
"If you go to the front page of my blog, I'll have a whole bunch of different stuff there, but then there are always links that go to the original article for where it's located on my blog," he says.
Cutts does actually appear to generally show the entire posts on the main page of his blog, though you have to click the link to see all of the comments and everything.
"So, as long as you don't have a completely duplicate blog post, where the whole things is completely there, it shouldn't be an issue, but even then, Google for the most part, is able to disambiguate and say, 'oh, this is a page that's refreshing pretty often,' and we have a pretty good idea that the actual content is linked to on these following pages," says Cutts.
"It is very common for people to have their main blog, and have the full text of their posts right there on the main page, and that works completely fine. So those are very similar situations, and in general, people haven't reported huge problems with that. So I think that's perfectly fine to do."
Long story short, as long as your posts link to the actual post pages, you'll probably be fine.