What is necessary to use Mobile Joomla with multiple domains? Thanks for
the GREAT extension.

Just create that domains as aliases to main domain and set them in Advanced tab of MJ settings.

Is it possible to use Mobile Joomla with multiple sub-domains for selection of a different mobile template for each sub-domain, not based on the device type?

I see there can be different sub-domains for the various devices like (Smartphone, iPhone, WAP, iMode) but I would like to be able to specify a mobile template specifically sub-domains regardless of the device.

Example:
mobileA.DomainA.com uses Template 1
mobileB.DomainB.com uses Template 2

We are using a Virtual Domain component that allows us to switch the desktop templates based on the domain, so we'd like to use a specific mobile template as well for each domain.