a clear yes and no 
If you have hosted blog solution google and co will not count the content as something that belongs to your website. YET! the content you submit there will be ranked higher because the blogs you write on will usually have a kick a** pagerank which – if you place links back to your website – you/your website will benefit from.
That being said: using a blog inside your website is interesting also. Reason being, that you provide your thoughts and insights on your corporate ID, etc. NOTE:! If you pull your feed into your website do not do it with frames because SEs will not index the content properly. Instead, use script to import the RSS feed, reformat it to fit your websites layout and then have it displayed there.
Related posts:
June 24th, 2009 - 6:04 pm
If you have a blog feeding into your web-site w/i a frame, does google count the blog as your web-site content? http://adjix.com/nft5
July 2nd, 2009 - 8:33 am
Reading Adjix http://ow.ly/gkZa