I have not done this, but have been considering doing it.

I would like to share modules (content), so I am limited to using one portal.  I plan on using the community edition to redirect a mobile device to a page of the current portal.  This will allow me to change the skin on this mobile page and reference existing modules in the portal for content.   I will change the skin on this mobile page to use a menu that is configured to display hidden pages and only child pages to the page that was redirected to.  This is how I will segregate the mobile pages from the rest of the portal.

Hopefully this plan will allow me to use the community edition with only core modules and be able to share content between the logical sites.  I know it will require me to create/alter my skin.

Unless of course someone has a better solution I could try.

Thanks,
Greg