Based on an advice of Laurent, I’m now testing newsgator, which is at the same time a news agregator and a blog publishing tool (this post is realized in newsgator). What’s really cool is that this tool is completely integrated in Outlook and has a publishing plug-in for blogger. Other ones already exist for Radio, .Text, MovablePoster, etc. (see here for the complete list).
First impression: the agregator part is well integrated in Outlook and very easy to set-up. The publishing part seems to be ok! I will use this tool for a while, stay tuned for more information in some days!
Second impression (after the first publishing): I have to check some details about the post process, specially the formatting and title parts ;-)