Originally Posted by fusionx

I thought that at first. I tried to submit a site map using top level categories as subdomains (business directory site) and google yelled at me.. can't do that as they are considered seperate sites. When I submitted site maps from each subdomain (minus all the common stuff like about us, contact us, etc, google smiled at me again

All the subdomains are getting indexed and ranked, and the primary domain shows solid backlinks from each subdomain. It's been that way for about two months now with no obvious problems.

There was some news on a site map/SEO list I read that Google might start accepting "hybrid" site maps that contain subdomain links and possibly even networked, directly related sites. That could be interesting to watch..