I think you may have come across this popular blog called thenextweb.com. This blog has a number of channels; i.e. sub-folders which are separate wordpress sites in themselves. For instance : http://thenextweb.com/google NextWeb.com is a wordpress blog in itself and these channels are separate wordpres blogs. However if you see everytime a new blog post is made to this channel, the main website immediately gets updated. Do you have any idea how to achieve this? I too want to create sub-channels for my main wordpress site but would like the main site to be updated with every post.
ohh?? You can Manually add links in the main blogs...! or either.. you can use some plugins..! let me look to find one for you..!
I have come across this before. The way i managed to make it work, i installed a plug-in that fetches rss feeds on my main site; then add your feed to the rss plug-in with the feeds from your posts on your sub-domain.