Here's a scenerio I have come across which would welcome input on; An old .com site has been replaced with new pages and structure (none of the previous pages exist on googles index as they were deleted), not a big deal as they were very poor.
The client wants a .co.uk version on the web as the 'priority domain'.
As a result the new .com has been blocked via a "no index" directive to avoid dupe issues and a .co.uk site was launched. Visibility or lack of it has become an issue for the .co.uk version.
Considering 301 redirect to carry link juice from existing backlinks (that still point to .com domain) or repoint the .com domain to the .co.uk site which I don't think will carry link juice?