Use Autoblog as function instead of the Recent Global Posts Widget?

Howdy!

I have a small blog network and at the network's first page I use the plugin "Recent Global Posts Widget" to display all of our bloggers posts.

If instead using plugin Autoblog and import entries to the network's first page (blog). And if I us the settings in the Autoblog plugin "Use full post or an excerpt" set to excerpt and link to the original source.

Now to my question.

Is there a risk of duplicate conten and risk to be punished by the search engines?

All our bloggers use their own domain that are mapped as primary domain.

Thanks.